Balotelli only returned to competition two weeks ago having been sidelined with a hernia problem since September.

Alessandria borrowed Torino's Olympic Stadium for the first leg of the Cup semi but Angelo Gregucci's men were a pale shadow of the side that had eliminated Palermo, Genoa and Spezia in previous rounds and will be hoping to do better at the San Siro in a week's time.

Balotelli, on loan from Liverpool, started up front alongside Brazilian Luiz Adriano, making his first debut since an aborted move to China last week, and should have put the visitors ahead before his 43rd minute strike from the spot.

Balotelli scuffed a volley on a Mattia De Sciglio cross at the near post early on then was let down by his first touch when clear through the middle.

Milan came close again just after the half hour when Andrea Pioli, who saw a goal chalked off for offside late in the second half, forced Alessandria 'keeper Gianmarco Vannucchi to parry with his legs.

Balotelli spurned another chance to open his account, springing the offside trap to run on to Keisuke Honda's perfect ball but despite rounding Vannucchi the striker hit wide.

When Luca Antonelli was brought down by Alessandria captain Santiago Morero as he ran in to the box, the referee pointed to the spot. 

Balotelli stepped up to send 20-year-old Vannucchi the wrong way and score his first goal since hitting the opener in a 3-2 win at Udinese on September 22.

Milan dominated the second half but it was far from impressive stuff and coach Sinisa Mihajlovic was openly frustrated on the touchlines.

Balotelli did well to snatch possession on the left flank to set up Honda with an inviting cutback but the Japanese midfielder's first-timer came off the head of a defender. 

Third-choice Milan 'keeper Cristian Abbiati was forced out to clear the danger as Adriano Mezavilla rose to meet a cross but the hosts rarely threatened.

Balotelli was replaced by M'Baye Niang on 70 minutes but before the Frenchman hit the far post in the closing minutes he was notably offside when Pioli's deflected shot sneaked past Vannucchi at his near post in the closing minutes.

On Wednesday, league and Cup champions Juventus host Inter Milan in the first leg of the other semi-final.