Sassuolo were held to a disappointing 0-0 home draw by AC Milan after Domenico Berardi missed a first-half penalty in their Serie A match on Tuesday.
Milan had keeper Mike Maignan to thank for salvaging the draw after he superbly saved Berardi's spot kick in the 23rd minute.
The penalty was awarded after Alessandro Florenzi tripped up Georgios Kyriakopoulos while tackling the Sassuolo defender with Alexis Saelemaekers, who also made contact with the player before his fall.
Davide Frattesi threatened AC Milan with a header close to the end of first half but was promptly denied by Maignan.
Rafael Leao had a chance to snatch a last-gasp victory for Milan after Charles De Ketelaere found him with a pass at the edge of the box but his strike was easily saved by keeper Andrea Consigli.
Milan, who top the table with eight points from four games, clash with local rivals Inter Milan on Saturday while Sassuolo travel to Cremonese on Sunday.
