After a scoreless first half, and numerous close calls from both squads, Giuly managed to find the back of the net in the 57th minute to give Barcelona the much needed win.

In front of a crowd of 76,833 fans, Barcelona found a way to quiet the home team offense and take the first-leg match.

In addition to applying pressure to the Serie A club in the second-leg match, the Barcelona victory also is a threat to Milan's record of having never lost a Champions League semifinal.

The win put an end to a 13-match home span without a loss for Milan.

Barcelona head coach Frank Rijkaard entered Tuesday's first-leg without some of the team's familiar faces. Henrik Larsson was forced out of the lineup after suffering a thigh injury in Friday's La Liga schedule, and Deco was out serving a suspension.

AC Milan was also missing a large part of its offense, as Filippo Inzaghi was ruled out due to a virus. Inzaghi's absence had coach Carlo Ancelotti relying on the offensive talents of the tournament's leading scorer Andriy Shevchenko and Alberto Gilardino, who is still waiting to score his first goal of the tournament.

Though the first goal didn't come until the second half, Barcelona managed to make a slight offensive stand in the opening minutes. Giuly hit his first shot in the seventh minute, but it was easily saved by Milan goalkeeper Dida.

Overall, the visitors managed seven shots on goal during the 90 minutes on the field.

Milan managed its best chance of the first half in the 14th minute, when forward Gilardino drilled a shot that hit the Barcelona post. Shevchenko managed another shot the very next minute, forcing Barcelona goalkeeper Victor Valdes to make another save.

Valdes would go onto save five Milan shots on target.

As the first half whistle was blown, both clubs left the field with a scoreless draw lingering into the second half.

But in the 57th minute, Giuly scored his first goal of the tournament to give Barcelona the edge. Giuly received a Ronaldinho pass, and then drilled a shot towards the Milan near post for the goal.

Both teams battled following the 57th-minute goal. Milan found its best chance at scoring the equalizer in the 82nd minute, when Kaka sent substitute Massimo Ambrosini through the Barcelona defense with a solid pass, only to see him shoot wide of the net.

Defender Paolo Maldini took another chance at goal for Milan by sending a shot off a corner kick towards the visitor's net. Valdes once again made the save, however, to preserve the one-goal lead.

With the game finishing 1-0, Barcelona now has a slight advantage entering the second-leg match at Camp Nou. AC Milan will have its final shot to advance to the next round on Wednesday, April 26.

The second match of the Champions League takes place tomorrow, with Arsenal playing host to La Liga club Villarreal.