Diego Costa popped up with a late winner as Atletico Madrid established the upper hand in their Champions League last-16 tie with AC Milan.
Milan bossed the first leg at the San Siro for long spells but ultimately the class of the Primera Division title challengers came to the fore as Costa capitalised on Ignazio Abate's poor attempted clearance from a corner to nod home a priceless away goal in the 83rd minute.
For much of the contest it seemed Clarence Seedorf's unrivalled Champions League pedigree might well guide Milan to a valuable win ahead of the return leg at the Vicente Calderon on March 11, but the Dutchman - four times a winner of this competition as a player - will have come away hugely frustrated after seeing his charges slip to a damaging 1-0 defeat.
Diego Costa celebrates his late winner at the San Siro
The outcome might have been different had Milan not come up against the formidable presence of Thibaut Courtois in the Atletico goal, the giant Belgium international producing two brilliant saves in the first half to keep out first Kaka and then Andrea Poli.
The game's decisive moment arrived with seven minutes left and is one that Abate will want to quickly forget as it was his attempted header from Gabi's corner that span high into the air and back towards his own goal. Costa still had plenty to do as he back-pedalled to get under the ball before leaping to nod in at the far stick - where a defender on the line should surely have been stationed.
The goal clearly deflated Milan, who had been good value for at least a draw, and when Adil Rami flashed a ferocious free-kick wide in the closing moments their last chance of salvaging a result had gone.
