Antonio Nocerino handed Milan the lead in the 55th minute from a corner kick. Clarence Seedorf sent the delivery to the near post where it was met by Robinho. The Brazilian then dropped the ball to Nocerino who powered a shot through traffic that eventually found its way into the back of the net.
Zlatan Ibrahimovic then converted a penalty kick nine minutes later to solidify its two-goal advantage and wrap up three points for the home side.
AC Milan is unbeaten in its last ten Serie A matches, jumping ahead of Juventus and Udinese and into first place with 31 points. Juventus and Udinese both have a game in hand, but enter Sunday's action trailing by one point.
Siena has lost four in a row in Serie A play, sitting just above the relegation zone with 14 points.
Chievo 2, Cagliari 0
Verona, Italy - Chievo jumped into eighth place in Serie A on Saturday with a 2-0 win over Cagliari at the Stadio M.A. Bentegodi.
Cyril Thereau gave the home side the lead in the 35th minute before Gennaro Sardo extended the advantage in the 57th minute to wrap up all three points and lift Chievo into the top half of the table.
Cagliari is tied with three other clubs on 18 points apiece, trailing Chievo by just a point.
Fiorentina 2, Atalanta 2
Florence, Italy - Stevan Jovetic scored in the 88th minute to help Fiorentina salvage a point against Atalanta as the two sides played to a 2-2 draw at the Stadio Artemio Franchi on Saturday.
Alberto Gilardino helped Fiorentina grab the lead in the ninth minute, a lead that last until the 81st minute when Andrea Masiello pulled one back for Atalanta.
Five minutes later, Atalanta went up thanks to German Denis, but it was quickly canceled out by Jovetic two minutes from time as the Montenegrin striker helped the home side save face with a draw.
Fiorentina and Atalanta remain tied in the Italian top flight, deadlocked at 17 points apiece.