Lionel Messi ended a brief goal drought with a brace as Barcelona made sure of their place in the knockout stages with a comfortable win last night.

The diminutive Argentine had not scored in any of his past three matches in the Primera Liga but broke the deadlock from the penalty spot after half an hour last night. Sergio Busquets doubled Barca's lead 10 minutes later and, though a Gerard Pique own goal gave Milan hope, Messi settled matters in the closing stages.

The result moves the Catalan club six points ahead of third-placed Ajax. As the Dutch champions have still to play Milan, it is impossible for both of them to overhaul Barca.

Milan, who have endured their worst start to Serie A in 31 years, came into the tie desperate to put their domestic woes behind them but they seemed content to sit back and wait for the chance to counter-attack, which allowed the home side to set the tone.

The breakthrough came on the half hour mark after Xavi expertly chipped over the Milan defence for Neymar, who was tugged back in the area by Ignazio Abate. Messi then fired straight down the middle from the spot for his first goal in four games, his last strike having come in Milan two weeks ago. Milan fell two behind in the 40th minute although it looked as if Busquets was offside before he headed Xavi's exquisite free-kick from the left past a helpless Abbiati.

The visitors unexpectedly reduced the deficit when Kaka dribbled past Dani Alves on the left and his cross cannoned off the unfortunate Pique past Victor Valdes, who had been a virtual bystander to that point.

Andres Iniesta and Sanchez went close to extending the lead again before Messi exchanged passes with substitute Cesc Fabregas and chipped over Abbiati seven minutes from time.