Simone Inzaghi felt Inter Milan were "perfect" as they beat struggling AC Milan 1-0 in the most dominant derby display he can remember.
Captain Lautaro Martinez's first-half header inflicted a fourth successive defeat on the Rossoneri at San Siro on Sunday.
Milan failed to register a shot on target and are down in sixth place in Serie A after their miserable winless run was extended to seven games.
The Nerazzurri, on the other hand, are second behind runaway leaders Napoli following a third win in a row after also seeing off their city rivals 3-0 in Supercoppa Italiana last month.
While Napoli look like they could be out of sight with a 13-point advantage at the summit, Inter head coach Inzaghi believes a commanding derby display shows they continue to make strides.
He said: "I'm very satisfied, I complimented the team because they were perfect, I don't remember a derby won and dominated in this way.
"We had a great derby, winning two in I think 20 days don't always happen. We don't look forward or backward in the standings, but only at us."
Under-pressure Milan boss Stefano Pioli went with a more defensive line-up in a bid to arrest the champions' slide, but Inzaghi's focus was on how his side approached the game.
He added: "There's been talk about it for days [Pioli's tactics]. I have to be honest that I was worried about mine, regardless of how Milan played.
"Every Sunday we meet three or four [man] defences. Tonight in the first half we bordered on perfection. In the second we did very well and conceded the first shot in the 75th minute. It's a great satisfaction."
Another big plus for Inzaghi was a substitute appearance for Marcelo Brozovic, the first time he has featured for Inter since November.
