AC Milan moved above Juventus and Udinese at the Serie A summit with a 2-0 victory over struggling Siena at the San Siro.

After a frustrating first half, the hosts finally made the breakthrough in the 54th minute through Antonio Nocerino.

Zlatan Ibrahimovic sealed the win with a controversial penalty in the 63rd minute, taking the Rossoneri a point clear of Juve and Udinese ahead of their matches on Sunday.

Siena's gameplan was quite clear - to frustrate Milan with a solid, organised defence and then hit them on the break.

For almost an hour of the game, it worked, and they even had the best chance to lead in the first half.

Ibrahimovic and Kevin-Prince Boateng both had good early chances for the Rossoneri, the former volleying over and the latter's shot saved on the stretch by Zeljko Brkic.

Francesco Bolzoni then almost put Siena in front in the 23rd minute when he nicked the ball past Milan goalkeeper Marco Amelia, but the ball shaved the outside of the far post.

A goal from the former Inter Milan midfielder really would have added to the home side's frustration at not being able to make the breakthrough.

The tension was lifted nine minutes into the second half, though, when Nocerino fired Massimiliano Allegri's side ahead.

Clarence Seedorf's corner was laid back by Robinho to the former Palermo midfielder, who drilled a low shot past Brkic into the bottom corner.

It was Seedorf's last involvement in the game as he was then withdrawn, with Alberto Aquilani taking to the field.

Eight minutes later, Milan were gifted the chance to double their lead when Boateng went down theatrically in the box and the referee pointed to the spot.

The Ghana international latched onto Robinho's through-ball and took a tumble over Brkic, who tried to move out of the Milan midfielder's way as he nudged the ball past him.

Ibrahimovic stepped up to score from the spot and condemn Siena to their fourth straight defeat, leaving them on the brink of the relegation zone.