19:45: Arsenal 1-3 AS Monaco
19:45: Bayer Leverkusen 1-0 Atletico Madrid
Away from London, Bayer Leverkusen take a slender advantage into their second leg against Atletico courtesy of a lovely goal from Hakan Calhanoglu. They were very impressive for large spells, but can perhaps count themselves slightly fortunate to have beaten Simeone's 10 men after Torres saw a goal ruled out in questionable circumstances.
A vintage away performance from Monaco and they will certainly fancy their chances of finishing the job and progressing to the quarter-finals next month. Wenger said he did not accept that his old team were underdogs in this tie and so it has proved.
A breathless finish at the Emirates and the final whistle brings boos from the home fans. Arsenal were just dreadful at times tonight and have handed a major advantage to Monaco ahead of the second leg.
Arsenal 1-3 Monaco
Bayer Leverkusen 1-0 Atletico Madrid
Wow. Just as Arsenal think they are back in this tie, Carrasco may have landed the killer blow with another masterful counter attack.
Oxlade-Chamberlain is dispossessed in the Arsenal half and the Belgian then leaves him trailing in his wake with a fantastic burst of pace and composed finish. Two-goal advantage restored and Jardim sprints down the touchline in celebration.
GOAL! Arsenal 1-3 Monaco (Yannick Ferreira Carrasco)
Arsenal handed a crucial lifeline in the dying minutes of the first leg. After a period of sustained pressure, a headed clearance finds it way to Oxlade-Chamberlain who shuffles his feet wonderfully to create space and unleash a lovely curled effort from 25 yards that gave Subasic no chance at all.
Goal! Arsenal 1-2 Monaco (Oxlade-Chamberlain)
Carrasco draws an angry reaction from his teammates as he shoots tamely at Ospina on the break.
Side netting for Sanchez as he fails to apply the finishing touch to Ozil's corner. Monaco make their final substitution as Bernardo Silva comes on for Martial. Five minutes remaining.
A third and final substitution from Arsenal as Rosicky replaces Cazorla. For Monaco, Dirar jogs off and defender Kurzawa is on.
Angered by the decision to deny his team an equaliser, experienced midfielder Tiago is dismissed for a second bookable offence.
Diego Simeone's team may choose to accept a narrow defeat now they are down to 10 men and take their chances at home.
RED CARD - Tiago (Atletico Madrid)
Atletico think they are level but the goal is chalked off in rather controversial fashion as a corner from Antoine Griezmann is not dealt with by Leverkusen and Fernando Torres turns home at the far post.
The officials rule that the corner went out of play before reaching the penalty area.
Applause from the away supporters as Berbatov is withdrawn. Carrasco replaces him.
We are approaching the last 15 minutes of both games now. Can Arsenal reduce the deficit? Will Bayer Leverkusen take a more commanding lead to the Vicente Calderon in March?
Arsenal looking extremely jittery in defence and are lucky not to be punished for their lack of concentration. Ospina lofts a poor ball forward to Oxlade-Chamberlain and the substitute is forced into a last-ditch tackle after a mishit pass from Koscielny.
Oxlade-Chamberlain is summoned by Wenger and replaces Francis Coquelin.
Nick Howson at The Emirates Stadium
A huge sense of anger has swept across the Emirates as Dimitar Berbatov, the former Tottenham striker no less, puts perhaps the tie beyond Arsenal after less than hour played of their last 16 clash.
"Arsenal may have begun the second half in the ascendency but they have adopted a approach which was asking for trouble. Monaco haven't been great tonight, but they haven't needed to be, merely preying on the deluge of Gunners errors.
Olivier Giroud is off for Arsenal, replaced by Theo Walcott after an evening to forget.
The rapid winger almost makes an immediate impact as his shot is saved by Subasic. Welbeck looked certain to notch on the rebound but his effort hits Walcott and loops over.
What a goal from Leverkusen and it's the least they deserve. Hakan Calhanoglu is the man who's got it, smashing home after collecting a wonderful backheel from the skilful Bellarabi.
Goal! Bayer Leverkusen 1-0 Atletico Madrid (Calhanoglu)
The night goes from bad to worse for Giroud as he blazes over from close range after Sanchez's fizzing effort is pushed into his path by Subasic. Woeful finishing.
Well, well, well. Despite dominating since the restart, Arsenal are now two goals behind after being hit on the counter. Woeful defending from Mertesacker sees the Gunners captain leave Martial with acres of space to run into and feed Berbatov who beats Ospina with an emphatic finish.
The home side are in all sorts of trouble here.