His celebration towards the Genoa fans did not go down too well, but the home fans were soon more disillusioned when the referee did not award a spot-kick after the ball struck Niang's arm inside the penalty area.

A push on Andreas Granqvist shortly after was also missed by the officials, further infuriating the home faithful.

That frustration turned to disbelief when Cesare Bovo's direct free-kick hit the post for the luckless hosts.

Ciro Immobile was introduced in place of Mattia Cassani on the hour mark by Genoa coach Davide Ballardini as he searched for a goal, which came within seconds of the former Pescara forward's introduction - but at the other end.

A misplaced pass by Immobile set up the Milan attack, which was finished by Balotelli, who left Frey no chance with his instant, diagonal shot.

Tempers flared soon after with Constant picking up his second yellow card after a clash with Bovo.

The home side had a few chances to reduce the deficit, with Granqvist moving into a more advanced position to give even more weight to their attack.

However, despite their best efforts, they were unable to find a route back into the game and they remained just five points above the drop zone, while Milan climbed to within two points of Napoli ahead of their clash at Chievo on Sunday.