M'Baye Niang put in a man-of-the-match performance to help AC Milan to a 4-1 Serie A win over Sampdoria at San Siro on Saturday, scoring two and setting up one more.

Sinisa Mihajlovic's men were fortunate not to go 1-0 behind early on when Roberto Soriano failed to take advantage of Gianluigi Donnarumma's mistake.

It was all Milan from thereon, though, and Giacomo Bonaventura opened the scoring after a sublime assist from Niang.

The Frenchman then converted a spot-kick for his first Milan league goal, adding a second after the break following an error from Emiliano Viviano.

Luiz Adriano rubbed further salt in the visitors' wounds in the 78th minute, with Eder's last-gasp penalty offering scant consolation to Vincenzo Montella's men.

Sampdoria nearly went a goal up within 30 seconds after Donnarumma got himself into trouble from a back-pass. The Milan goalkeeper hesitated too long and Soriano picked up his poor clearance, immediately firing a shot toward the empty goal, only for the 16-year-old to redeem himself with a superb save.

Alessio Cerci was denied by an offside flag in the ninth minute after tapping home the rebound from Carlos Bacca's powerful shot, but the home side did grab the lead soon after.

Niang went past his marker down the right before sending in a perfect cross for Bonaventura, who blasted home from close range.

Bacca then tried his luck with an ambitious effort from 20 yards out on the half-hour mark, but the Colombia international saw his volley go just wide of the target.

Milan doubled their lead in the 38th minute when Niang converted a penalty. Lorenzo De Silvestri pulled Bonaventura to the ground inside the area, leaving referee Daniele Doveri no other option but to award a spot-kick, and the 20-year-old confidently stepped up and found the net with a powerful attempt.

Niang nearly made it three shortly after the break with an acrobatic backheel after Cerci's free-kick, but Viviano did well to push the ball wide for a corner.

The Sampdoria goalkeeper handed Niang a gilt-edged chance to get his second goal of the game in the 49th minute with a sloppy goal kick and the in-form attacker happily accepted Viviano's present, making it 3-0 with a calm finish.

Bonaventura came close to scoring his second of the game after a superb cross from Ignazio Abate, but Viviano managed to keep his volley out in two attempts.

The former Atalanta man again tried his luck halfway through the second half from a free-kick, yet his curled shot over the wall went just wide.

Substitute Luiz Adriano should have made it four in the 77th minute, but the Brazilian aimed wide from five yards out.

The former Shakhtar Donetsk did get his goal shortly after, though. He controlled Cerci's cross with his chest before firing in a volley from inside the area.

Eder pulled one back from the spot in the 87th minute after being fouled in the area by Andrea Poli, but it mattered little.