Arsenal, with a sense of injustice, after Robin van Persie sent controversial since they made the Champions League against Barcelona at the Nou Camp after a 3-1 loss to the left.
The Dutchman was the inclusion of the shock of the Gunners, who led 2-1 in the round, faster than the knee injury he expected in the Carling Cup final suffered recovered.
However, moments after his goal against Sergio Busquets was the first goal from Lionel Messi penalty canceled after a terrible mistake van Persie, Cesc Fabregas orders given by the Swiss referee Massimo Busacca.
Van Persie was booked in the first half and showed a second yellow card for lashing the ball into the goal from a striker offside call marginal Arsenal said he could not hear.
Barcelona took advantage, with Xavi and Messi penalty put the link of Arsène Wenger, who left to reflect on what could and should now be for the Saturday quarter-finals of the FA Premier League title rivals Manchester United were the Cup
As expected, Barcelona will on offense kickoff greeted by a crowd of 95,000-strong passion in the Camp Nou.
Laurent Koscielny an important element from the beginning as Peter and the visitors do not think they were greeted by a deafening cacophony of whistles.
Koscielny and Jack Wilshere combine to prevent, if Messi to get a signal of the new possession gave Arsenal too expensive.
The Gunners were in a change after 16 minutes when goalkeeper Wojciech Szczesny by Manuel Almunia was forced to do after an injury to his left hand to replace a routine backup of Daniel Alves long shot.
Barcelona continued to press Arsenal, Johan Djourou to produce excellent operating economics compared to deny Xavi Peter to the rebound over the bar for details.
Barcelona, then almost fin first goal on 35 minutes when a pass from left back wound Adriano hit the outside of the post.
The anger spread when Wilshere went to ground while stretching for a loose ball on the edge of the penalty area in Barcelona, players said that a dip to Van Persie and former Liverpool midfielder Javier Mascherano out before squaring became quiet.
Van Persie has not calmed down and was a needless yellow card on the stroke of half-time for lighter than Alves.
Fabregas back to his childhood club for the first time, then inexplicably tried to pick up the ball on the edge of the Wilshere Arsenal's penalty area, but it was ok for Andres Iniesta.
Messi - who scored four goals for Barcelona in last season's game here - was absent, and chipped Almunia brilliantly before lashing the ball into the empty net.
Arsenal faced a tough battle before the second half, but a lifeline on 53 minutes presented.
Samir Nasri got away on the left side and won a corner when I was in the field of six meters in the opener with his own goalkeeper Director Busquets.
The link then took another twist when van Persie through ball broke, but it was offside, appeared to be the marginal cost.
The Netherlands before hitting the ball well and showed a second yellow card, followed quickly by a red cross.
Van Persie, Arsenal and could not believe what I said the attacker, who could not hear the whistle.
Barcelona began almost immediately on the attack, the first David Villa Messi then denied by a brave Almunia few blocks.
The Catalans finally regain the lead in the 68th minutes as Xavi slotted home to play in a faster exchange between Iniesta and Villa.
Before joining Arsenal, Barcelona could have a penalty when Messi released Koscielny Peter and slotted into the bottom corner in Barcelona, rub shoulders with the last eight years to go.
Wenger sent on Nicklas Bendtner and Andrey Arshavin to replace Cesc, but he was more hope than expectation inches
Almunia denied another goal by Messi Barcelona with good blocks and replaced by Ibrahim Afellay.
Bendtner was placed next to connect to the Wilshere Cruz in the penalty area, but it should be for the Gunners.
