Zlatan Ibrahimovic and Patrick Vieira scored a goal each on Sunday to help Inter Milan beat Palermo 2-1 and take a four-point lead in the Serie A.
Ibrahimovic put Inter ahead in the sixth minute with a powerful strike from 30m, which Palermo goalkeeper Alberto Fontana should have saved. Vieira scored the second in the 61st from just inside the area.
Inter improved to 33 points, four ahead of AS Roma, which moved past Palermo and into second place following its 4-2 win over Sampdoria. Palermo is third with 27 points.
Inter dominated the match with its most controlled performance of the season.
"The team played very well this evening, in what we knew would be a difficult game," Inter coach Roberto Mancini said. "In the first half we were extraordinary ... the defense conceded practically nothing."
Mancini left in-form striker Hernan Crespo on the bench, instead handing Adriano his first start in more than a month. He recently took a week off in Brazil to regain his focus.
The forward, who has not scored since March, did not break his goal-drought but showed glimpses of the form that saw him net a total of 40 goals in the 2004-2005 season, for club and country.
The burly striker provided assists for both goals, troubled Fontana with a free kick in the 27th minute, and hit the side-netting three minutes later.
Inter's ninth straight victory in all competitions set a club record. It was Palermo's second straight loss in the league, after going down 1-0 to Cagliari last week.
Francesco Totti scored two goals to keep Roma in the title chase.
The Roma captain beat Sampdoria's offside trap in the 13th minute to give his team the lead, then added a spectacular 74th-minute volley from the left.
Simone Perrotta and Christian Panucci scored Roma's other goals in the first half, after Sampdoria's Sergio Volpi had equalized for the hosts in the 14th minute.
Sampdoria forward Francesco Flachi also converted a 90th-minute penalty on his return from a two month suspension for betting.
Roma, which won its fifth straight, has now scored 11 goals in its last two league matches.
Also on Sunday, Reggina rallied from two goals down to draw 2-2 with fourth-place Livorno and move into positive points for the first time after starting the season with a 15-point penalty from the Italian match-fixing scandal.
Lazio beat winless Ascoli 3-1 off goals from Manuel Belleri, Goran Pandev and Pasquale Foggia.