Basel looked to have salvaged a level first leg finish late on but Luiz's last-gasp free-kick puts Chelsea firmly in command ahead of the second leg at Stamford Bridge. Thanks for your company this evening and I'll see you all soon.
FT: Basel 1 Chelsea 2
What a finale! Luiz's free-kick on the edge of the box incredibly slips away from the fingertips of Sommer and Chelsea have their lead restored right at the death!
GOAL FOR CHELSEA - LUIZ!
Degen pushes on to meet Stocker's flick, weakly driving the ball across the face of goal which sees Cech get down quickly to snuff it out.
Incredible scenes as Chelsea fail to put the ball in the net through both Terry and Moses, with Sommer then punching clear from the proceeding corner.
Four minutes of added time to be played.
Mata takes, but his left-footed shot swerves away from goal, drawing the frustration of Benitez in his technical area.
Schar is booked following a poor challenge on Moses, following a splendid run that gifts Chelsea a free-kick 20 yards out.
Two immediate chances present themselves for Chelsea, with Torres unable to sort his feet out before Oscar drives the ball over the bar from 10 yards.
Cech dives to his left, Schar strokes the ball down the centre and Basel are level on the night!
GOAL FOR BASEL - SCHAR!
Penalty to Basel! Azpilicueta slides in to clear the ball, and seemed to do so, with Stocker going down under him as the hosts are presented with the chance to level up.
Zoua's cut-back from the byline is cleared behind by Cole as Basel push on from that free-kick and earn a corner.
Degen is left in some distress following that injury, and although the stretcher is on, the full-back makes his own way off the field in more positive scenes.
Luiz also gets his name in the referee's book for a nasty tackle on P Degen.
D Degen urges Luiz back to his feet after a trip on his fellow midfielder, with Chelsea looking considerably firm all over the pitch. Even if they do concede tonight, it would be brave man to back against Chelsea progressing to the final.
Mata's delivery to the back post finds Ivanovic lunging in, but he can't direct the ball on target and it's a Basel goal-kick.
D Degen hauls down Oscar in his first act on the pitch, earning him a yellow card and conceding a needless free-kick 20 yards from goal.
Oscar takes the place of Lampard.
The second Degen enters the game as that poor touch from Salah is his last of the first leg.
As Mata declines the opportunity to shoot, Lampard doesn't, and wastes a good period of pressure for Chelsea with a wayward shot.
Dragovic leads a swift break, feeding in Salah whose first touch lets him down and allows Cech to sprint out of his goal and make the collection.
The lively Streller continue to impress, but after taking on Frei's through ball, he can't get a shot away and inadvertantly carries the ball out of play. Chelsea goal-kick.
A trip from Schlar allows Lampard time to collect the bouncing ball, but a crucial tackle from Diaz prevents the midfielder's shot from reaching the target.
Zoua plays in Diaz superbly, but upon setting himself to shoot just inside the box, he aims his right-footed effort just over the bar. Great chance for the substitute.
Schlar wastes a tidy passage of play from Basel with a launch that sends the ball well into the stands from long-range.
Mata's miraculous close control sees him keep progressing away from Dragovic, but Ramires is offside as he played in before Torres' close-range is denied excellently by Sommer.
Mata takes to the field for Chelsea with Hazard the man taken off.
Yellow card for Dragovic after a poor tackle on Torres.
Frei's magical pass in behind Terry finds Zoua, but the Chelsea captain denies his cut back supremely as another home attack is brought to an end.
Cole is out of the second leg as he picks up a yellow card for time wasting.
A neat attempt from Frei flashes narrowly wide as the hosts come closer to breaking Chelsea's vigilant back line.
Hazard orchestrates a counter attack fro Chelsea following a nervous piece of Blues defending as Streller struck on goal, but his ball wide to Moses is picked up in the end by Park.
El-Nenny is also hauled off by the hosts as Zoua enters the fray.
Park looks to cut inside Ivanvovic, but finds his progress thwarted as Chelsea look to push on from defence with Hazard, who sees a corner awarded to Chelsea after a poor touch from Degen.
A midfield battle ensues as teams look to control the ball, with neither doing so until Park's strides forward down the left result only in a Chelsea corner.
Good work from Terry denies Stocker with a firm tackle, before Degen launches the ball forward moments later for the striker as Cech rushes out to claim.
Die makes way for Basel with Diaz his replacement.
A Lampard corner is knocked away by Dragovic, but Basel can't muster a quick break following a poor Die touch and they are pushed back swiftly.
The corner falls to Streller at the far post, but the striker didn't seem to be expecting it in the slightest and he ends up essentially clearing behind for a Chelsea goal-kick.
A quick-fire Basel break results in the ball switched from right to left, with a touch from Luiz on the byline seeing the home side earn anpther corner.
Stunning skill from Hazard sees him play back to Torres from the byline, before the Spaniard sees his shot denied by the post as both teams clatter the woodwork in the second half.
Die concedes a foul on Luiz, which Chelsea play short as the game continue to remain relatively back-and-forth for the time being.
Stocker uses his body to muscle Ivanovic out the way to accept Frei's pass, and with that the referee awards Chelsea a free-kick.
As Hazard is hacked down by Schlar, a throw-in is the decision when Chelsea arguably should have a free-kick for that incident.
El-Nenny's corner is cleared as far as Park, but as the left-back plays it back in, the man who took the corner is rather poorly caught offside.
Stroller hits the post! After exceptional work from the striker he carves out to chance to shoot inside the penalty area, watching his strike come off the woodwork as Ivanovic hacks behind.
A penetrating run from Hazard nearly culminates with a shot on the edge of the box, but Schlar steps in with a timely tackle to deny the Chelsea forward.
Basel get the action restarted.
Alan Sams writes: "Comfortable half for Chelsea soaked up what little pressure Basel had to offer and broke well from the back, Hazard should have scored though."
A thoroughly impressive Chelsea deservedly lead at the break and arguably they should have slotted home a second against a Basel team who look inexperienced in comparison. Send your second half thoughts to firstname.lastname@example.org and @JWoodfield365
HT: Basel 0 Chelsea 1.
An even better chance involves the same two men once again, as Torres feeds in Hazard, who knocks the ball wide from 15 yards as Sommer rushed out to deny him. Chelsea really should have had a second there.
Torres was initially cleared through, but after pulling up to allow options to arrive, he misses an attempted overhead kick before Hazard fires wildly over the bar. Good chances for 2-0.
Luiz's spectacular overhead clearance sees another Basel move come to an end, with Chelsea cutting out every killer final ball the hosts attempt at the moment.
Ivanovic does well after slipping to deny Streller, with Park losing out following a Terry tackle as Chelsea continue to look solid thwarting Basel's attacking ideas.
Salah clatters into Terry as the two vied for the loose ball, with the Chelsea defender coming off worse as the Blues win a free-kick.
Patient bulld-up from Basel sees them retain control in the final third, with Ivanvovic eventually forced to boot the ball away for a throw-in.
Die sets Degen away on the break, but after slipping near the touchline, the right-back collides with the advertising boards and the move comes to an end.
Lampard advances, but upon initially losing out Chelsea regain the ball, with Ramires eventually poking the ball at goal, with a strong hand from Sommer and clearance from Dragovic denying the midfielder a goal.
Sublime skill and control from Hazard sees him retain the ball and continue his run, before a Moses shot from the left is collected well by Sommer.
Salah lifts the ball into the six-yard box following more good work from Streller, but the alert Cech makes the early claim ahead of the arriving Stocker.
Ivanovic is adjudged to have fouled Sommer as the keeper came to collect the delivery and the free-kick is given by the referee.
Torrres cuts inside Dragovic superbly before unleasing a shot on goal which comes off Schar and travels behind goal. Chelsea corner.
Moses looks to link up with Hazard, but he takes a tumble under the defensive Basel bodies, with Hazard forced back with the ball as a result.
Terry runs the ball out of play upon a battle with Degen, and Basel switch the ball from right to left as they pressure Chelsea's goal.
Streller's dangerous cross looked like it may have crept in at the near post, but Cech is alert and turns it round for a corner which in the end was not given.
Die and Schar prevent Chelsea's attack through the centre, winning back the ball before controlling it in defence as the Blues press to retrieve it.
Moses capitalises on a failed Basel attack, charging at Frei and Schar, with a touch off the latter taking the ball behind for a corner.
Streller almost finds Stocker with a sensational ball inside Azplilicueta, but the ball runs away from him as Basel continue to build some momentum in their quest for an equaliser.
Terry heads away, but Die keeps the move alive, before Dragovic's somewhat aimless ball towards the back post finds no team-mate in support and it's a Chelsea goal-kick.
Frei's flick on to Degen is brilliant, but as the full-back progresses, his delivery takes a touch off Terry and Basel win themselves a corner.
The combative Die hauls down Hazard upon trying to win back the ball and that foul on the Belgium forward earns Chelsea a free-kick.
Good work from Salah in the final third results in El-Nenny once again letting rip, but his effort travells narrowly over the bar, a solid strike from 25 yards.
Chelsea survive the corner, and Moses leads the counter attack before Park slips in on Luiz and retrieves the ball. Moments later, Salah falls after a coming together with Ivanvoc, but much to his chagrin, no penalty is awarded.
Ivanovic concedes a free-kick on Streller, and Schar lines up a sensational strike that requires fingertips from Cech to tip it over the bar.
Park plays down the line for Stocker, but it's a pacey ball and the striker can do nothing but let the ball drift out of play in the end.
Die looks for Streller as Basel aim to respond, but Terry steps in to intervene and Ramires collects the ball as Chelsea resume possession.
There was some initial confusion as to the ball last came off from the corner, but replays show that it's Moses who pokes the ball past Sommer and as a result Chelsea have a priceless away goal. Basel 0 Chelsea 1.
GOAL FOR CHELSEA - MOSES!
Sommer makes the first decent save of the match, denying Lampard's flick at the near post following Azpilicueta's ball in.
Streller picks out Die with a pass across the park, but Moses tracks back to get his head on the end of the ball and reclaims possession for Chelsea.
Moses steers the ball away from Schar, but Degen covers behind his team-mate and makes a timely tackle to prevent the winger's progress.
Sommer claims the corner with confidence, but a throw out is retrieved by Lampard, who forces the goalkeeper into more action as he plucks his cross out at the near post.
Chelsea probe in the final third, with Moses' delivery from the right met by the diving Dragovic who concedes a corner for his troubles.
Stocker charges in on Ramires, winning the ball and not conceding a free-kick as Basel reclaim possession imposingly in midfield.
Hazard collects possession down the right, drawing a herd of Basel defenders in the process, before playing back to Ramires, whose delivery into the box is cleared by Schar.
The corner is played short, and finds El-Nenny trying his luck from range, with Cech at full stretch before seeing the ball narrowly land behind goal.
Corner to Basel as Stocker is played out wide before crossing in from the left which sees Ivanovic steer the ball behind.
Ramires heads on Lampard's pacey ball forward, but he loses control in the process, leaving Basel to break down the right where Cole marshalls Salah.
Chelsea get the semi-final underway.
Sky Bet make Chelsea slight favourites at 11/8 ahead of Basel, priced at 9/2, while the draw can be backed at 5/2 tonight.
Analysing that team news, left-back Ashley Cole returns from a hamstring injury for Chelsea. John Terry starts in defence alongside midfielder Frank Lampard, with David Luiz pushed forward to accommodate the captain, while Victor Moses is also included in a side showing four changes following last weekend's draw at Liverpool. Ryan Bertrand, Oscar, Juan Mata and John Obi Mikel drop to the bench, while Swiss champions Basel field the same starting XI which began the second leg with Tottenham.
Jake Willis writes: "I can see this as a good game of counter attacking football from both sides and it's great to see Luiz back in midfield. I still think Chelsea will have the upper hand though so going for Basel 2-4 Chelsea. Torres to score one at least, Lampard and Terry to also score and Hazard or Torres again, still undecided!"
Chris Green begins the predictions, writing: "Good evening everyone!! This is crunch time for Chelsea and I really hope they win here this evening but easier said than done. Whether you are playing FC Basel at home or away, it will always be a difficult match because they have players that can pose a threat to any team. Chelsea will have to perform good tonight in order to get a result because if they don't, I see FC Basel making the most of the Blues' mistakes... My prediction for this evening's game: FC Basel 1-1 Chelsea."
Basel: Sommer, Philipp Degen, Schar, Dragovic, Park, Fabian Frei, Salah, El-Nenny, Die, Stocker, Streller. Subs: Vailati, David Degen, Diaz, Cabral, Sauro, Steinhofer, Zoua.
Chelsea: Cech, Azpilicueta, Ivanovic, Terry, Cole, Luiz, Lampard, Ramires, Hazard, Moses, Torres. Subs: Turnbull, Mata, Oscar, Mikel, Cahill, Benayoun, Bertrand.
Good evening folks and welcome to live coverage of Basel v Chelsea in their Europa League semi-final first leg. Following the Blues' FA Cup exit two weeks ago, this competition is now the only chance for silverware for Rafa Benitez's team this season, although the interim Chelsea boss has admitted that finishing in the Premier League top four remains his priority. In that respect, the team sheet will make for interesting reading. Send your messages to email@example.com and @JWoodfield365 throughout the evening.
Kick-off is at 2005 GMT.