[UEFA CHAMPIONS LEAGUE] Diego Milito stole the show from fellow Argentine Lionel Messi, scoring once goal and setting up two more as Inter Milan stunned defending champion Barcelona, 3-1, in the first leg of their UEFA Champions League semifinal series.

Never had Barcelona lost by more than one goal since Pep Guardiola took over as head coach in 2008 and it looked to be coasting at the San Siro after Zlatan Ibrahimovic fed Pedro for an easy goal in the 19th minute.

But the Inter defense tightened and shut down Messi, who had four goals in his previous Champions League game against Arsenal, and Milito took over -- but not before missing two open shots.

The 30-year-old Argentine found Dutchman Wesley Sneijder wide open on the left side for the equalizer on the half-hour mark.

Three minutes after halftime, Milito fed Brazilian right back for the go-ahead goal and put the game away himself with the third goal.

Barca defenders protested that Milito was offside before he headed the ball past goalie Victor Valdes, but Portuguese referee Olegario Benquerenca allowed the goal to stand.

After the game, Barca playmaker Xavi allegedly complained to Inter coach Jose Mourinho, who is also Portuguese, that he had his countryman, Benquerenca, to thank for the win.

Mourinho shot back at the postgame press conference that Barcelona players were sore losers.

“It’s always difficult to lose for those who aren’t used to losing," he said. "I’m like that too. It’s the characteristic of a team which always wins. I can never have a problem with Xavi because I adore him. He’s one of best in the world.”

Barcelona took two days to get to Milan by bus because of air travel restrictions caused by Icelandic volcano and often looked out of sorts. It had never allowed a goal in four previous meetings with Inter in the Champions League -- two in the group stage of this season's competition.

"I congratulate them," said Guardiola, "but we'll see them next week. We are in the semifinal of the Champions League against a great team, it can happen. We move forward."

April 20 in Milan
Inter Milan 3 Barcelona 1. Goals: Sneijder 30, Maicon 48, Milito 61; Pedro 19.
Inter Milan -- Julio Cesar, Maicon (Chivu 74), Lucio, Samuel,Zanetti, Motta, Cambiasso, Pandev (Stankovic 56), Milito (Balotelli 75), Sneijder, Eto'o.
Barcelona -- Valdes, Dani Alves, Pique, Puyol, Maxwell, Xavi, Busquets, Keita, Ibrahimovic (Abidal 62), Messi, Pedro.
Referee: Olegario Benquerenca (Portugal).
Att.: 83,000