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Christian Pulisic scored the only goal in the second half to keep Milan just about in touch with the top two.

The Rossoneri went into the contest having picked up only one victory from their previous three league matches, leaving them 12 points behind city rival and table topper Inter Milan.

Sassuolo is the only team to have beaten Inter in the league this season but it has been in poor form, having won just one of its previous 11 matches and none of the past four.

Milan had Luka Jovic available after he picked up an ankle injury against Salernitana last time out, and the Serbian was named among the substitutes.

The hosts had the ball in the back of the net after only six minutes when Ismael Bennacer slotted it in but an obvious offside in the build-up meant it was quickly chalked off.

Tijjani Reijnders was the next to threaten with a shot well wide, while Bennacer did well to create a shooting opportunity on the edge of the box but sent his effort just past the near post.

Milan thought it had found the breakthrough 31 minutes in when Rafael Leao drilled the ball into the top corner but he was again denied by an offside flag having mistimed his run.

Sassuolo looked lively on the break and two minutes later Domenico Berardi forced Mike Maignan into the first real save of the match with a long-range effort that was tipped over the bar.

The visitors have leaked goals too readily this season but they would have been happy with their first-half display, and Milan was limited to brief glimpses in the early stages of the second half as well.

However, with 59 minutes gone, Pulisic tucked away the opener, the American timing his run perfectly to meet Bennacer’s pass into the box.

Ruan Tressoldi desperately tried to intercept but could not divert the ball away from Pulisic, and he beat Andrea Consigli in the Sassuolo net.

Armand Lauriente tried to get the visitors back on level terms but he was stretching as he hit his shot from the edge of the box and it was easily stopped by Maignan.

Milan boss Stefano Pioli sent on 18-year-old Kevin Zeroli for his senior debut, and it almost grabbed a second in the 78th minute but Alessandro Florenzi’s well-struck volley dipped just over the bar.

Substitute Samuel Chukweze had the final chance but his search for a first Serie A goal goes on after shooting narrowly wide of the far post.