Staff Reporter.
AC Milan missed the chance to go top of Serie A as Sassuolo came from behind to earn a surprise win at the San Siro.
Simon Kjaer then turned into his own net before Domenico Berardi added the visitors’ third in the second half.
Romagnoli was shown a straight red for bringing down Gregoire Defrel late on.
Milan, who are now three games without a win in the Italian top flight, remain second, but leaders Napoli can build a three-point advantage by beating Lazio at 19:45 GMT.
Sassuolo’s success was their first in four games.
“We lacked a cutting edge,” Milan coach Stefano Pioli told DAZN. “We got too much wrong in key situations, especially in the opposing area.
“We missed the last pass or the attack on the goal. We had to manage the one-goal advantage better and instead we made a mistake that proved costly.
“It is clear that if we have now conceded seven goals in two [league] games, something did not work.”
Milan came into the contest on the back of the defeat in Florence last weekend — their first of the season in Serie A.