Referees favour Barcelona, claims Zlatan Ibrahimovic, after two Lionel Messi penalties knock AC Milan out Messi stepped up to score his second spot kick of the match to put the hosts back in front, before Andres Iniesta's second-half goal sealed the win. The ball wasn't in play and he called it. It was weird, odd, it ruined the game," Ibrahimovic said. I still don't understand what he whistled. If he calls those he should call the others. Without him the game would have been 50-50. Barca eliminated Arsenal last season in the quarter-finals after Robin van Persie was given a second booking for continuing to play after the whistle had gone early in the second half, with the game tied 1-1. In the semi-finals, Real were left with 10 men for most of the second half of their 2-0, first-leg defeat when Pepe was red carded, which led to Mourinho's criticism. "Sometimes the referee made too many concessions," Milan coach Massimiliano Allegri said. I don't know if it proved decisive. We made a mistake on the first penalty but he helped on the second. Playing Barca is never easy. Barcelona coach Pep Guardiola offered few apologies after leading his team into the Champions League last four for a record fifth straight season. Only Real Madrid have achieved such a feat in the history of the European Cup, on their way to a record five straight triumphs between 1956-60. "You can talk all you want about referees but that makes it five straight semi-finals, the fruits of our talent and a lot of work," Guardiola said. Apart from the penalty, Ibrahimovic - who played one season for Mourinho at Inter - did not leave with an entirely sour taste in his mouth. "It was a good experience, we lost the game 3-1 playing against the best team in the world," said Ibrahimovic, who joined Barcelona from Inter in 2009 in a swap that included striker Samuel Eto'o. We were there until the second penalty, and this we have to discuss.