Most years, the Inter Milan-AC Milan derby has Scudetto implications, but Sunday's derby was for bragging rights only.
With its 2-1 victory, Inter opened up a 25-lad on AC Milan heading into the holiday break.
Argentines Julio Ricardo Cruz and Esteban Cambiasso scored for Inter, which rallied after going a goal down to a Andrea Pirlo free kick in the 18th minute.
"Inter-Milan is an important game for what the two teams represent beyond titles," Cambiasso said. "For us this was a chance to close out a magical year -- the one with the record-filled league title. We were able to beat Milan for the third time in a row and that's important for the fans."
The win maintained Inter's nine-point lead over second place Roma, a 2-0 winner over Sampdoria, and clinched the first-half championship.