That's me done for evening. Thanks for your company, and all of your tweets and emails. Commiserations to the West Ham fans who have seen their side bow out of the competition. Fergie's boys may have stumbled into the next round, but could they be on the path to more FA Cup glory? See you all soon!
And that's it! Manchester United move into the fourth round and have a home tie with Fulham waiting for them. West Ham fans will be haunted by that late Van Persie goal at Upton Park - they were so close!
Full time: Manchester United 1-0 West Ham
90 + 1
Still hope for West Ham with a throw in of their own high up the pitch. It's another deep cross into the box but there's no danger this time and Lindegaard gathers it up. That could be it for the visitors!
Good footwork from Giggs earns Man Utd a throw in and they're in no hurry to take it. Three minutes of added time...
Bad challenge from Scholes on Matt Taylor and he's in the book. Looks like he took a caution for the team there!
... but the cross is over hit and the hosts get it away comfortably. West Ham have started to press higher up the field now. It's something they should have done ten minutes ago but can it pay off?
Hernandez has the ball in the net! But it's offside by some distance. Great ball from Giggs to find Chico free. A better effort than Rooney's penalty that's for sure. West Ham have another free kick in a good position now...
Andrew Forbes e-mails to say: "United struggling without RVP. How many Man U fans were labelling Arsenal a one man team last season? Wonder where they would be without him."
Six minutes plus injury time for West Ham to find an equaliser. Looks like the home side are ready to play for time to hang on to their lead now. Can the Hammers get back into this and force extra-time at Old Trafford?
Well, well, well. Fergie turned away in disbelief after that penalty. West Ham need to capitalise and thump another high ball into the box. United aren't defending these well, but West Ham aren't attacking them well either...
There's a change for West Ham too. Youngster Elliott Lee is on for Ricardo Vaz Te
Man United bring on Scholes for Nani
That's terrible! Rooney balloons it over the cross bar and West Ham are still in this.
Man Utd have a spot kick. Spence is guilty again, leaving his arm out. Referee didn't think twice about that one.
Jordan Spence goes into the book for a late challange.
A nervous Ryan Ainley tweets: "United are struggling we can't rely on RVP all the time. We need to pick it up!!"
Taylor does the right thing and goes for a first time shot on the edge of the area but it's well wide. This is what West Ham need to be doing though. There's still 15 minutes to go and nothing to lose. Start throwing the chips down and take a gamble.
Another chance goes a begging for West Ham. Good work from Vaz Te and Nolan sees the latter free in the area. But he tries to cut inside rather than take the shot first time and gets the ball stuck under his feet.
Rooney's attempted through ball is too quick for Hernandez. And the home fans are groaning moments later as Valencia skies an attempted cross over the crossbar. Can someone get me a battery? The energy seems to have drained out of this game.
Gareth Bull e-mails to say: "United need to finish this game off we can't rely on RVP to come off the bench again. Wake up united."
Man Utd are passing the ball for fun at the moment. Nani has a chance but slices his cross into the side netting. This really isn't good enough from the Hammers and they haven't got long left.
It's Man United's turn to bring on a fresh pair of legs and Michael Carrick comes on to face his former club with Anderson making way.
Good save from Jaaskelainen. Rafael breaks free in the area and slides a tasty ball to Hernandez who gets the better of Jordan Spence. The keeper's quick though and gobbles up the ball before the Mexican can get his foot behind it.
Double change for West Ham: Jack Collinson comes on for Diame and Kevin Nolan is on for Carlton Cole
Another chance goes begging for the Irons and it's Matt Taylor again. A good back heel find him free but it's a wild attempt and Lindergaard watches it fly over the bar. Big Sam looks up to the sky in frustration.
Anderson has a pop from distant but I think the fan in the upper tier has it covered. Moments later Nani sends a good cross in but Jaaskelainen is alive to the danger and scoops it up in front with Hernandez lurking.
Great chance for West Ham! A good ball escapes the foot of Jones and Matt Taylor is free in the area. Plenty waiting but Rafael is back to clear it with Cole waiting at the back post. That could have been 1-1.
Man United's turn for a free kick after needless tug by Diame. It's nodded behind for a corner but that's soft and the Hammers clear it away. Valencia thumps it back in and Jaaskenlainen catches it easily.
Another shout for hand ball from West Ham but that one's hit Rooney on the head. The ball is loose in the box from the resulting corner but again the visitors aren't capitlising. United are being careless in defence and West Ham need to punish them.
Free kick in a decent position for West Ham. Gary O'Neil is over it but goes for the dinked effort and it's cleared by Phil Jones. It was a fair way out but we all know O'Neil can hit them. Would a shot the better option there?
A bit end-to-end now but neither side has threatened. Rafael finds himself in space down the right but his cross is deflected comfortably into the hands of Jaaskelainen.
Corner for West Ham bobbles around in the area but no Hammers player can get a foot on it. The chances are there for Big Sam's men but they need to start making more of them.
Was that hand ball? Carlton Cole flicks up the ball in the area and it seems to come off the thigh and arm of Rafael. If that was a lucky escape for Man United then West Ham have survived an even greater one. Hernandez breaks free but hammers his ball over the bar. A let-off there.
The Hammers have had more of the ball at the start of the half but need to to use it to greater effect. Carlton Cole is out-muscled by Phil Jones and can't get on the end of a looping ball from Vaz Te.
It's back underway at Old Trafford. Fergie's men dominated the opening 45 minutes but West Ham still have a chance. What can Big Sam's men do to stay in the FA Cup? Taking a shot might be a good start...
Josh Waughman tweets: "Proud of this performance! Diame running the show for us, Danny Potts another amazing talent, Were still in this!"
Does Big Sam need to make a change? How vital is a second goal for Man United? Let me know what you think by tweeting @MattSkyCycling or e-mailing firstname.lastname@example.org
Dave Egerton tweets: ""Do you reckon anyone will own up and admit to steeling the atmosphere from old trafford?"
I'll be honest, I've seen better halves of football, but it wasn't a stinker either. United got their goal and seemed content to trundle along in mid-gear for the rest of the period. West Ham have offered a decent amount going forward, but they have got virtually no penetration and are consequently relying heavily on balls into the box, which Phil Jones and Chris Smalling have so far been repelling without too much trouble.
Half-time: Manchester United 1-0 West Ham
Intuitive play from Giggs just now. A gap opened up in midfield and he suddenly surged into it and in doing so immediately put the entire West Ham defence and midfield on the back foot. Neat interplay between Nani and Hernandez then almost created a shooting opportunity, but Alou Diarra managed to get a vital foot in.
Wonderful strike from Rooney just now. He picked the ball up on the left, cut inside past a defender and sent a right-footer hurtling towards the near-post bottom corner that Jaaskelainen had to be sharp to get down to save.
Man United haven't really got out of about third gear here - but then again they haven't really had to. They've got their goal and are happy to let West Ham push on in the hope that they leave gaps to exploit.
Nani looks to catch the eye by shooting from about 40 yards. It wasn't a bad effort, clearing the crossbar by about five foot, but it was never going to fly in from there.
Mazin Nasralla tweets: "Very quiet at Old Trafford tonight. Guess the regulars aren't quite as impressed as you Matt. This is tedious."
Decent spell of possession for West Ham in the Man United half but the hosts were well organised and weren't about to let the visitors through. The passage ended with Gary O'Neill over-hitting an attempted ball over the defence out for a goal kick. That summed up West Ham's inability to play through Man United, and re-emphasised their dependence on balls into the box.
Major let-off for West Ham as Jaakelainen (how many times am I going to have to write that?!) uncharacteristically drops a fairly routine cross into the box but gets away with it. Meanwhile, Buttner has just hit the post, albeit from a cross that Jasskelainen this time had covered.
James Wade (not the darts player) has got a keener eye than me. He tweets: "23rd min it was handball not shoulder barging from cole. Still did both...."
Man United weren't finished there, though, because the ball was whipped back into the box and Chris Smalling drew a smart save from Jaaskelainen with a point-blank header. Back up the other end, Vaz Te has just seen a deflected right-foot shot from an angle saved by Lindegaard. West Ham aren't buckling here - they're offering plenty in attack.
Rafael has just gone on a Mo Farah-esque gallop through midfield that caused no end of trouble for West Ham. It led to a corner, from which Nani has just had a rasping shot brilliantly cleared off the line by teenage defender Dan Potts. Excellent defending.
West Ham have gone to Plan B. Or is it Plan A? Either way, they're starting to pump balls into the box and play for set pieces, which to be fair, is going to be the best chance here. Carlton Cole has just spoiled a decent free-kick from a dangerous position by shoulder-barging about three Man United defenders on his way to giving away a needless foul. "Me?" Yes, you, Carlton.
Half-chance for West Ham as they win a corner on the left that falls to the feet of James Tomkins, but his snapshot was blocked almost the moment it left his boot and Man United cleared.
The goal seems to have dealt a fairly major blow to West Ham's belief, because all the pace has ebbed out of their game and things are starting to look more hopeful than purposeful. Man United, on the other hand, are looking very comfortable in possession.
Another chance for United as Nani collects the ball midway into the West Ham half, cuts inside and shoots, but his right-footed effort from 20 yards was weak and Jussi Jaaskelainen gathered it easily.
Just before the goal, West Ham had a great chance when a scuffed Lindegaard clearance presented Ricardo Vaz Te with a sight of the net, but the Portuguese forward opted for an early shot and didn't really get hold of it.
Fine, fine goal from the hosts as Anderson releases Javier Hernandez in behind the West Ham defence in the left channel, and the Mexican squared for Rooney to slide the ball into an empty net. Beautifully done but West Ham cut open a tad too easily.
Goal! Manchester United 1-0 West Ham (Wayne Rooney)
Man United are starting to call the shots now, with Ryan Giggs orchestrating things in the centre of midfield. Their latest passage of high-tempo play ended when Buttner fired a left-footer over from 30 yards. Ambitious.
But then West Ham go up field and win a free-kick in a tasty position on the left. Gary O'Neill sweeps it in and after a spot of pinball, Man United hoof it clear. Feisty game already.
Not the best start for West Ham, it has to be said. Straight from the kick-off, Man United went up field and won a corner inside 30 seconds. Fortunately for the travelling fans, the hosts attempted a short corner and nothing came of it.
Ryan Ainley tweets: "I reckon 3-1 united Rooney grabbing 2 Hernandez grabbing 1 and Carlton cole grabbing a last minute goal."
And we're off. West Ham are in all blue, incidentally, and Phil Dowd is the referee.
I've just re-read what Ben Foulkes said below - hat-trick for Buttner? Really? Come off it. I'll eat my keyboard if that happens.
Just a thought: anyone else think Roy Keane looks like President Ahmadinejad? Actually, forget that, because the teams are emerging from the tunnel, which means we're just moments away now. Sit back and enjoy what hopefully should be a decent game.
Ben Foulkes e-mails to say: "5-3 to united today with a hat trick for buttner and 2 for Rooney."
Right then, people, this is your 10-minutes-till-kick-off warning. Last chance to get the kettle on, the biscuits out, and the nails ready to be chewed. Go, go, go...
Stefan Howarth e-mails to say: "United 3-1 West Ham. Chicharito grabbing 2 and Nani grabbing the other. Hope Nani can finally prove his worth!"
Another old friend has got in touch. The wonderfully named King Jones, all the way from Botswana, e-mails to say: "We were very unlucky not to have snatched a win last time round, though i must admit that if it were not for Collison's mighty head, we would have told a different story. To be brutally honest we were completely outplayed, all we did was pump long balls forward and hoped for some sort of confusion from the United defence. As a Hammers fan i will admit today we have no chance, my sympathies for all the travelling fans. No prediction, just hoping for some magic."
Ross Bartlett tweets: "Easy game for man utd tonight with Rooney and Nani back am going for 4-0 utd come on u RED DEVILS!!!"
William Spearing, who may or may not be a relation of Liverpool/Bolton's Jay, but probably isn't, e-mails to say: "Disappointed in Big Sam, talk about giving Man Utd an easy game! We're gonna get smashed tonight by at least 3 goals!"
Richie Farman e-mails to say: "Best thing about the return of Rooney, Welbeck on the bench,long may he stay there."
I've only got one more fact, I'm afraid (cue cheers), and I've saved the most trivial till last: The last three matches between Manchester United and West Ham United in all competitions have featured three goals in the last 15 minutes. Well I never.
Back to the facts (cue groans): Robin van Persie has scored five times in his last four appearances (in all comps) against West Ham United.
Scottie tweets: "Loving that email from Darren Molloy 'Rooney with a hatrick" c'mon you super reds'."
Adam Swayne on the e-mail can smell goals tonight. He says: "I think Man Utd will win but not comfortably a 3-2 win Rooney, Nani and Van Persie for Man Utd and Cole X2 for West Ham."
A quick reader comment intermission and then back to the factathon. Morgan Roberts e-mails to say: "Good mix from Fergie, playing time from the likes of Rooney, Ando and Nani returning tonight, as well as giving Jones and Smalling game time in there natural positions. Nothing but a comprehensive United win with Rooney and Chicha getting in on the act."
This one also carries a bit of clout: West Ham have failed to score in their last four trips to Old Trafford in all competitions, losing all four.
Actually, I take it back. These super-boring facts aren't actually that boring. For example: Robin van Persie has scored five times in his last four appearances (in all comps) against West Ham United.
Right, last one for now and then I'm gonna hit you with some super-boring and completely irrelevant pre-match facts. Hardevbadhen tweets: "I think Manutd will be on there game today glad rooney and nani's back Rooney,Nani and Buttner, Van Persie if need be"
Our old friend Josh Waughman tweets: "With Diame back I'm slightly confident & With no lazy Nolan I reckon a cheeky 2-1 West Ham!"
Jono Bastyan e-mails to say: "Good to see Anderson back in the fold, he was impressive before his injury. Rooney to score a brace. I would rather see Ferdinand in the starting line-up though!"
Darren Molloy is sounding confident on e-mail. He says: "Good chance for Rooney to bounce right back in this game. Hatrick for Rooney you heard it first :)"
Aidan O'Neill from Belfast e-mails to say: "Rooney and Chicha back for tonight. 2 goals from each of them should see a comfortable 4-1 win with C.Cole scoring first?"
Tom Hooton e-mails to say: "I think it will be an easier fixture this time round for united with rooney scoring 2 and nani scoring as well, 3-0 to united for me, UNITED!"
George from Reading e-mails to say: "Nolan and Collison on the bench...nice one Sam forget tonight game over turn the lights off now. Waste of time for our travelling fans at least we could have a go at them."
Despite their scare at Upton Park, United are 1/4 to complete the job at Old Trafford in normal time and 1/9 to qualify. The Hammers are 19/2 to pull off a shock win or 5/1 to progress after extra time or penalties. If you fancy a United romp it's 7/1 for a 3-0 triumph or 11/1 for 4-0.
Scottie tweets: "I think West Ham were very unlucky last time around but I also think Man United will have an easy win this evening."
MUFC News tweets: "Expecting a huge game today, we slacked in the first game but with the confidence after derby I can see it being a big win."
Martyn Langley tweets: "if west ham play the way they did last time round they could snatch this from united but I'm thinking its gunna be 2-1 ManU"
So that's just the 10 changes for Manchester United then, with returns for Rooney, Nani, Anderson and Lindegaard. West Ham have gone for a slightly toned-down six changes, with Joe Cole, Kevin Nolan, Matt Jarvis and Jack Collison among those dropping out after the defeat to Sunderland.
West Ham team: Jaaskelainen, Spence, Tomkins, Reid, Potts, Diarra, O'Neil, Diame, Taylor, Vaz Te, C.Cole. Subs: Spiegel, Demel, Jarvis, Collison, Nolan, Lletget, E Lee.
Manchester United team: Lindegaard, Rafael, Smalling, Jones, Buttner, Anderson, Valencia, Nani, Giggs, Hernandez, Rooney. Subs: Amos, Ferdinand, Carrick, Scholes, Kagawa, Van Persie, Welbeck.
I'm already getting an avalanche of comments from you guys, which I'll publish as soon as I've given you the team news...
Farhaan Fajandar e-mails to say: "What a thriller on our hands. Lets hope Rooney and Nani have a good game!"
West Ham came so close to not being here tonight as they went into injury time in the first match 2-1 ahead. But then a certain Robin van Persie decided to spoil the party with a sublime piece of strike play, taking down Ryan Giggs' raking diagonal ball with a divine first touch before sweeping a low shot into the bottom corner.
Welcome along to our live text coverage of Manchester United v West Ham United in their FA Cup third-round replay at Old Trafford. I'm Matt Westby and I'll be talking you through all the build-up and then the match itself. If you've got anything you want to get off your chest, tweet me @MattSkyCycling or e-mail email@example.com and I'll be happy to publish what you have to say - as long as it's family-friendly, of course. Hope you enjoy the game.
Kick-off is at 2005.