Zlatan Ibrahimovic scored a brace as champions Inter Milan thrashed struggling AS Roma 4-0 at the Stadio Olimpico on Sunday to move two points clear at the top of Serie A.
The Sweden striker was on target at the start of both halves before Dejan Stankovic and Victor Obinna completed the rout with powerful shots from the edge of the area in the 54th and 56th minute.
"The team was smart, the players were concentrated and they interpreted the work we have done well," Inter coach Jose Mourinho told Sky television.
"I'm happy about the three points, about the result, which has a special meaning in a big match, but I'm also happy about the way the team played."
Three teams are tied in second place with 14 points - Catania, who beat Sicilian rivals Palermo 2-0, Udinese, who drew 2-2 at Lecce, and Napoli, 2-1 victors over Juventus on Saturday.
AC Milan are a point further back after Ronaldinho struck twice and Filippo Inzaghi scored a late goal to secure a 3-0 win over 10-man Sampdoria.
Last year's runners-up Roma fell to their fourth defeat in seven games despite the return of captain Francesco Totti, who made his first start in the league this season after knee surgery, and are nine points off the pace.
Inter seized the initiative in the fifth minute when Ibrahimovic galloped from just beyond half way to latch on to a long ball and lob Roma keeper Doni from outside the box.
He beat Doni again with a diagonal strike two minutes after the break before goals in quick succession by Stankovic and Obinna hammered Roma's morale further ahead of Wednesday's trip to Chelsea in the Champions League.
At the San Siro, Ronaldinho converted a 55th-minute penalty conceded for handball by Sampdoria defender Stefano Lucchini, who was sent off, and doubled the lead 11 minutes later after some nice interplay with his compatriot Kaka down the left.
Inzaghi dodged past keeper Luca Castellazzi to slip the ball home in stoppage time and make sure Samp stayed without a league win.
Lazio, leaders before the weekend's action, fell to fifth alongside Milan on 13 points after losing 3-1 at Bologna.
Sergio Volpi's free kick and forward Marco Di Vaio's brace in the first half ended Bologna's run of five consecutive defeats, with Tommaso Rocchi pulling one back for the Rome club shortly after the break.