The referee blows his final whistle, AC Milan 2-0 Barcelona
Milan are heading for a famous win that would make Barca's mission in the second leg difficult.
Milan substitute Traore receives a yellow card for a challenge on Mascherano.
The referee adds five minutes of stoppage time.
Barcelona defender Carles Puyol is replaced with Argentinean midfielder Javier Mascherano.
Milan make another substitution, Bakaye Traore replaces El Shaarawy, who looks to have picked up an injury.
Milan will be looking to maintain their two-goal advantage in the remaining minutes, a result which will make them favourites to advance to the quarter finals at the expense of the mighty Barcelona.
Milan are defying the odds with a solid and efficient display, restricting Barca to tame efforts and hitting them on the break.
Ghanaian midfielder Muntari, who is found unmarked, doubles Milan's advantage with a superb volley at the far post after being set up by El Shaarawy.
81 GOAAAAAAAAAAAAAL FOR MILAN!!!
With 10 minutes remaining, Barcelona are expected to pour forward to equalise. A night to forget for the disappointing Catalans.
A curling free-kick by Barcelona midfielder Xavi goes over the crossbar.
Barca go close to leveling the score!! Iniesta sends a right-foot shot that goes just wide, the best chance for the Catalans so far.
Milan make their first substitution, 19-year-old forward M'Baye Niang replaces Giampaolo Pazzini.
Barca are regaining possession, but they are still struggling to break down a superb Milan backline. Their passes are repeatedly intercepted in front of the 18-yard box.
An attempted bicycle kick from Pazzini goes straight to the hands of Barca keeper Victor Valdes. Milan look the more likely to score another goal.
Milan striker Giampaolo Pazzini receives treatment after being hit in the face by Puyol's head in an aerial challenge.
62 Barca make their first substitution. Chilean winger Alexis Sanchez replaces Cesc Fabregas.
60 Milan look determined to double their lead. Barca will need to improve to avoid conceding another goal.
58 The referee ignores the protests of Barcelona players and allows the goal to stand. Milan are leading.
57 Ghana's Kevin-Prince Boateng scores a dubious goal, firing a low shot home from inside the area after a shot from Montolivo struck the arms of Kevin Constant.
57 GOAAAAAAAAAAAAAAL FOR MILAN!!!
55 The match remains very dull, with both sides unable to mount threats.
54 Barcelona midfielder Sergio Busquets receives a yellow card.
49 Both sides continue from where they left off in the first half. Barcelona dominate possession, Milan defend in numbers.
The second half is underway
45 The referee blows his half-time whistle, AC Milan 0-0 Barcelona
40 Neither side look likely to score, five minutes before halftime.
36 El Shaarawy just fails to get on the end of a right-wing cross from Boateng.
33 Milan are resorting to counter-attacks but Barca defender Carles Puyol is producing a spirited display, cutting short the hosts' attempts.
30 Barca had the better possession in the second quarter of an hour, but they could not carve out openings, thanks to Milan's steadfast backline.
29 Barcelona are still desperately trying to break down Milan's resolute defence.
25 Milan defender Philippe Mexes is booked for fouling Lionel Messi.
23 Milan midfielders are superbly closing down spaces, intercepting passes from the likes of Xavi, Cesc Fabregas and Lionel Messi.
19 A long-range shot by Barcelona midfielder Xavi is handled by Milan keeper Christian Abbiati.
17 Moments later, Boateng fires wide from inside the area as Milan pile on pressure.
16 Stephan El Shaaraway wastes a golden opportunity for Milan!! He breaks clear after a through pass from Kevin-Prince Boateng but his poor dribbling allows Carles Puyol to clear the danger.
15 The first quarter of an hour saw shy attempts from both sides to break the deadlock. No clear-cut chances yet.
14 AC Milan defend in numbers when Barca seize the ball. Maybe that's the only way they can stop the threat of the Catalans.
9 A cross by Barcelona's left-back Jordi Alba is cleared by Milan's defence. Barca are starting to gain control.
7 AC Milan are attempting to send through balls behind Barca's backline, but their efforts are not successful.
5 AC Milan midfielder Sulley Muntyari sends a long-range left-foot volley over the bar.
3 Both sides make a cautious start.
The match is underway
21:15 Both sides stepped onto the pitch for the routine pre-match warm-up, 30 minutes before kick-off.
20:40 AC Milan’s starting line-up: 32-Christian Abbiati; 20-Ignazio Abate, 17-Cristian Zapata, 5-Philippe Mexes, 21-Kevin Constant; 23-Massimo Ambrosini, 10-Kevin-Prince Boateng, 18-Riccardo Montolivo, 4-Sulley Muntari; 11-Giampaolo Pazzini, 92-Stephan El Shaaraway.
20:40 Barcelona’s starting line-up: 1-Victor Valdes; 2-Dani Alves, 3-Gerard Pique, 5-Carles Puyol, 18-Jordi Alba; 6-Xavi, 16-Sergio Busquets, 8-Andres Iniesta; 4-Cesc Fabregas, 10-Lionel Messi, 17-Pedro.
20:30 AC Milan have won only once in 10 meetings with Barcelona since their famous 4-0 victory over the Catalans in the 1994 final.
19:00 Barcelona, on the other hand, are formidable. They lead the Spanish La Liga table with 65 points, a massive 12 ahead of nearest challengers Atletico Madrid.
18:45 Milan are struggling this season after offloading several of their stars last summer, including striker Zlatan Ibrahimovic and defender Thiago Silva. They lie fourth in the Italian Serie A table with 44 points, 11 behind leaders and defending champions Juventus.
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