Arsenal 2 Crystal 0. Oxlade-Chamberlain the star of the show with two goals which send Arsenal back to the Premier League summit.
Oxlade-Chamberlain is taken out by his team-mate Rosicky. We're in stoppage time now.
Oxlade-Chamberlain is trying to stretch his calf, might have pulled it. Worrying for Wenger, who has used all three subs.
Arsenal block two efforts from Palace, a free-kick and a follow-up shot.
Double change for Arsenal: Gibbs and Bendtner on for Ozil and Giroud. Job done for the Gunners.
Gayle replaces Chamakh, who gets a warm reception from the Arsenal fans.
Ozil's deflected strike from 20 yards is easy for a diving Speroni.
It's all Arsenal now, and I think Palace will be doing a lot of ball chasing in the closing stages.
The question is: Are you watching Roy Hodgson? Oxlade-Chamberlain has excelled in a central midfield here, and could be an option for England in Brazil this summer.
Arteta is urged to shoot by the home fans but chips a delicate pass over the Palace to Giroud, who is closed down quickly.
Arsenal are popping the ball about the park now - will be a tough final 15 minutes for the visitors.
Giroud fed the ball to Oxlade-Chamberlain, who then took centre stage, powering past Ward into the Palace box and slotting a right-footed shot past Speroni into the bottom corner. Great finish.
2-0 to Arsenal! Oxlade-Chamberlain
Arsenal make a change, with Podolski making way for Rosicky.
Puncheon breaks down the left flank, then tees the ball up for Bannan, who lifts a left-footed strike over the crossbar.
Delaney goes into the book for a late tackle on Cazorla.
Gabbidon gets away with a clumsy looking tackle on Podolski in the box - Arsenal probing away as they look for a killer second goal.
Arsenal, meanwhile, are looking to rack up a ninth win at home. Chamakh is flagged for offside.
Palace are showing some good spirit but face a tough task to get back into this, having lost nine of their 11 away games so far.
Cazorla puts in an excellent tackle to stop Bolasie and concede a corner, which eventually comes to nothing.
So an hour has gone and Arsenal look well placed to get the victory which will send them back into top spot. Oxlade-Chamberlain fires an ambitious shot high and wide.
Palace are now playing a 4-5-1 with Chamakh up front.
Podolski tracks back and defends well to earn a goal kick after some Palace pressure.
Pulis makes a change, sending on Bannan for Jerome.
Arsenal have upped the tempo since scoring and their passing has taken on a greater confidence and purpose.
Podolski fires into the sidenetting after some nice build-up play from Cazorla and Arteta. The atmosphere is buzzing now.
Arsenal try to calm things down in possession, then Podolski powers into the Palace box and wins a corner.
GREAT SAVE! Palace respond well, with Puncheon's left-wing cross headed by Bolasie to Jerome at the far post, where Szczesny blocks his close-range shot with a brave save.
Tony Pulis didn't look a happy chap on the touchline - must be fuming to concede so early in the second half.
Cazorla gets the assist after threading a glorious pass to Oxlade-Chamberlain, who kept his composure to dink the ball over Speroni and into the net. It's Arsenal 1 Palace 0. Game on!
1-0 to Arsenal - Oxlade-Chamberlain!
Tony Pulis has switched his wingers, with Bolasie on the right and Puncheon on the left.
Jerome is fouled by Arteta on the halfway line as Palace have some early possession.
The players are out for the second half - and we're away.
Sky Bet's odds have changed: They've got Arsenal to win 1/2, a draw at 2/1 and a Palace win at 10/1.
Any readjustments of your predictions after that first half people?
Niall Quinn: "Maybe it's time for someone from Arsenal to have a crack and pull the trigger from 25 yards."
So it's Arsenal 0 Crystal Palace 0 at half-time. Palace have defended with discipline and organisation, and when Arsenal have got a rare sight of goal, Speroni has pulled off some good saves. Tony Pulis will be the happier of the two managers at the break.
We've had two minutes of first-half stoppage time but not a lot to report. Palace breaking up the flow of the game with some crunching tackles and good closing down.
Monreal crosses from the left flank and Gabbidon clears for a corner, which is well cleared by Jedinak before Koscielny has a crack from 25 yards, only to see his shot fly well wide.
Ward's cross into the box goes straight to Szczesny - should have done better with the position they were in.
The free-kick is flicked goalwards by Mertesacker but it's a comfortable save for Speroni.
Ozil takes a tumble after Chamakh pulls his shirt, and the Palace forward goes into the book.
Monreal crosses from the left but Gabbidon clears. Pulis will be very happy with this troops so far.
Podolski's powerful run lifts the crowd but Palace clear the danger after Ox loses possession.
Giroud does his bit at the back, clearing the corner with a header, and Arsenal are back on the ball once again.
Palace earn a corner after some committed build-up play.
Sagna is hobbling gingerly but is trying to run the shake off.
Speroni saves bravely to deny Sagna as he tries to get on the end of a fine Arteta pass into the box. Sagna receiving treatment.
Arsenal are a little bit laboured in their build-up play and could do with showing some more intent in the final third.
Ozil's free-kick is slightly flicked on by Koscielny but Speroni makes a fine diving save to parry the ball to safety.
The natives are getting slightly restless, then Delaney fouls Giroud for an Arsenal free-kick 30 yards from goal. Ozil over it.
Palace are struggling to make the ball stick when they get into the attacking third - but Chamakh draws a foul from Mertesacker.
Tony Pulis has won five and lost five since taking charge of Palace.
So half an hour has gone at The Emirates and it's all square. Palace look composed and well-drilled, and don't mind letting Arsenal dominate the possession.
Bolasie does well and charges out of defence before feeding Jerome, who is fouled by Oxlade-Chamberlain.
Arsenal now try their luck down the right, with Sagna providing the width. Giroud goes down looking for a foul but gets nothing.
Ox tries an ambitious forward pass but no-one is on his wavelength so it goes out for a goal kick.
The final ball is just letting Arsenal down at the moment, with Palace's tight marking doing its job perfectly.
Arsenal really concentrating on the left wing and force a corner after some intricate play. Palace clear the danger for a throw-in.
Top-class defending from Mertesacker, who brings real composure to the Arsenal backline.
Cazorla tries to get a pass in behind the Palace defence, but puts too much weight on a ball to Giroud on the left flank.
Arsenal are trying to find a way through the heart of the Palace defence and maybe need to spread the play a little wider.
Palace haven't parked the bus as such as they've got two up front, but all the outfield players know their jobs and are working hard.
Koscielny is looking solid at the back and tackles Puncheon well. Palace are trying to slow the game down, much to the frustration of the home fans.
Tony Pulis lost every game here as Stoke manager.
Podolski goes down theatrically but gets nothing from the ref, then Palace break quickly, only for Chamakh to overhit his pass.
Arsenal produce some stunning one-touch football on the edge of the box but Palace hold firm and keep their shape.
Palace try to set Bolasie free down the left wing but the pass is slightly overhit and goes out for a free-kick.
Chamakh threatens for Palace but overhits his touch, allowing Szczesny to race out and snuff out the danger.
Joe Ledley and Tom Ince have just been shown watching on from the sidelines - Palace did some great deadline-day business.
The early possession stats are Arsenal: 76%, Palace 24%. Long afternoon ahead for the Eagles players.
Cazorla is the man who pulls rank on the free-kick - but steers his effort high and wide of the target.
Dikgacoi gives away a foul on Podolski in a dangerous position around 30 yards out.
Jedinak gets a good tackle in as Arsenal edge towards their 18-yard box following a flowing move.
Speroni pulls off a fine save to deny Monreal's left-footed shot after a fine lofted pass into the Palace box by Ozil.
Arsenal are playing from the back and will have to show patience today - Palace can't get the ball off them.
Oxlade-Chamberlain (I might call him Ox from now on) is looking comfortable in the early stages and seeing plenty of the ball.
Arsenal are pinging the ball around nicely but Palace are well organised and are going to be a tough nut to crack today.
Ozil, Cazorla and Arteta combine nicely on the right flank before Jedinak fouls Oxlade-Chamberlain for a free-kick.
The Arsenal centre-backs get their first touches of the ball as the hosts start to get their passing game going.
Palace, the men in black, boss possession early doors.
The whistle blows and we're off and running.
Arsenal go for their 4-2-3-1 line-up, with Oxlade-Chamberlain and Mikel Arteta in central midfield, and Olivier Giroud up front.
Former Arsenal striker Marouane Chamakh leads the line for Palace, alongside Cameron Jerome, with the visitors lining up in a straight 4-4-2 formation.
Arsenal will be looking to put the pressure on title rivals Chelsea and Man City, who lock horns in Monday Night Football's 'Showdown' at The Etihad.
Palace have punched their way out of the relegation zone, but Saturday wins for West Ham and Cardiff mean they are still looking their shoulders as they lie one point above the drop zone.
Arsenal have conceded just six league goals on home soil in 11 games so far, while Palace have scored five goals in 11 games on the road.
Arsene Wenger: "I've picked a team with plenty of experience and Premier League quality. Oxlade-Chamberlain is playing in central midfield, which is where I think his future lies."
Palace starting XI: Speroni, Ward, Parr, Jedinak, Gabbidon, Delaney, Bolasie, Dikgacoi, Jerome, Chamakh, Puncheon.
Arsenal starting XI: Szczesny, Sagna, Monreal, Cazorla, Mertesacker, Koscielny, Oxlade-Chamberlain, Arteta, Giroud, Ozil, Podolski.
Tony Pulis: "It's going to be a tough game - Arsenal are what they are, and that's one of the best teams in the Premier League."
Opta: The Gunners average 1.84 points per game in Premier League London derbies and Palace 0.90 per match. These are the best and worst points returns respectively of any capital clubs.
Opta: Crystal Palace have scored just five goals away from home in the Barclays Premier League, fewer than any other team and never more than once in a single match.
Here are some Opta stats for you: Arsenal have won five and lost none of the last eight meetings with Palace in all competitions.
Paul Merson thinks it will be 3-0 to Arsenal, saying: "I think this is a home banker. I'm not saying Arsenal are going to run riot and win 5-0 or 6-0, but I expect them to win by two or three. I have seen Palace a lot and they are very well organised and they caused problems at Man City, but Arsenal will have miles too much for them. I say Arsenal will win, but what Palace have done since Tony Pulis took over has been phenomenal; I'd be surprised if they went down."
Chris Green from Huddersfield says: "Arsenal to win 4-1, with Cazorla (2), Podolski and Giroud notching up the goals."
Lydia Collier says: "Just like to say I think it will be 4-1 to Arsenal with Giroud scoring a hat-trick."
Richie Sesay has been in touch and says: "I'm an Arsenal fan, all I can really see here is a home win, I say 3-0 to the mighty GOONERS!!!
If you fancy a flutter on the game, our friends at Sky Bet are offering 1/5 for an Arsenal win, 11/2 for a draw and a whopping 16/1 for a Palace away win.
Send me your thoughts on the game and any predictions to firstname.lastname@example.org, or let me know on Twitter @SimonJWilkes.
Arsene Wenger's hosts will be looking to return to the top of the Premier League table after seeing Manchester City assume pole position in midweek - but can they grab all three points against Tony Pulis' stubborn Eagles?
Good afternoon, and welcome to our live commentary for Arsenal v Crystal Palace at The Emirates.
Live updates will appear here...