Bojan Krkic scored the only goal of the game in the 12th minute, earning Frank Rijkaard's side an important away goal on top of the slender lead they take into the second leg.

Schalke were outplayed in the first half before coming to life in the second, but they were unable to find a goal, leaving them with a mountain to climb at the Nou Camp next week.

Barcelona's trident of Thierry Henry, Krkic and Samuel Eto'o sparked the tie into life early on.

Henry's shot was fumbled by Manuel Neuer, but the Frenchman squared the rebound to the unmarked Krkic who tapped in from two yards.

Schalke kept up the pressure in the second half with Fabian Ernst's shot only inches away from Asamoah after Pander had waltzed past Gianluca Zambrotta and Xavi in the 70th minute.

But Barca held on to move a step closer to a possible last-four clash against Manchester United.