Wenger was reported to have had a furious row with Busacca in the tunnel after the game before also complaining to UEFA officials and allegedly telling Guardiola he should “congratulate” the referee.

With Arsenal holding a 2-1 lead from the first leg, Lionel Messi brilliantly levelled the tie before Sergio Busquets’ own goal restored Arsenal’s advantage.

However, Arsenal’s night went quickly sour as Van Persie was controversially dismissed for time-wasting after shooting despite being whistled for offside, before Xavi’s neat finish and a Messi penalty saw Barca home.

The Gunners failed to register a shot all night and had just 31% possession, before and after Van Persie’s dismissal.

Wenger admitted speaking to Busacca – though there were reports it was more like a row than a discussion – and claimed UEFA officials were also “shocked” by the referee’s decision.

On his conversation with Busacca, Wenger said: “I think he must think he made the right decision.”

He added: “I spoke to UEFA people. They are shocked as well because it killed a promising, fantastic football match.

“What for? If it’s a bad tackle or a second bookable offence okay, but frankly it is embarrassing.”

Barca coach Guardiola felt his side were good value, although he did understand Arsenal’s grievance.

And he revealed he also failed to avoid Arsenal’s boss on the warpath.

“Arsene Wenger told me I should congratulate the referee,” Guardiola said.

Arsenal held firm in the face of constant Barca pressure for 45 minutes but in first-half added time, Messi brilliantly flicked the ball around substitute goalkeeper Manuel Almunia to put his side a goal up on the night and level on aggregate.

The Londoners regained their overall lead early in the second half, however, as Busquets headed past his team-mate Victor Valdes in the Barca goal.

But Arsenal’s fight was undermined three minutes later when Van Persie was harshly shown a second yellow card for shooting at goal after being caught offside.

Barca’s pressure told again in the 69th minute when Xavi finished off a trademark move to put the match level on aggregate.

The tie was won two minutes later when Laurent Koscielny felled Pedro in the box and from the penalty that followed, Messi coolly placed his side in the Champions League quarter-finals.

Guardiola believes his side were better overall in the two legs.

“The reality is they didn’t have three passes in a row all night,” said the Catalan coach.

“They are a top Premier League team and did not have a shot on goal.”