AC Milan overcame a series of defensive lapses to beat Cagliari 4-3 on Sunday, while AS Roma captain Francesco Totti marked his return from knee surgery with a hat trick in a 3-1 win over Bari.
Clarence Seedorf, Marco Borriello, Alexandre Pato and Ronaldinho scored for Milan at San Siro. All of Totti's goals at the Stadio Olimpico came in the first half.
Sampdoria beat 10-man Chievo Verona 2-1 to move back into the Champions League places. A goal from Marco Rossi put Samp ahead in the 19th minute and Chievo was reduced to 10 men just before the break with a red card for Luciano.
Antonio Cassano provided the pass for Giampaolo Pazzini to score Samp's second in the 65th minute before Andrea Mantovani pulled one back for Chievo 10 minutes from time.
Inter Milan leads with 32 points, Milan has 25 and Juventus and Sampdoria have 24 each.
Inter defeated Bologna 3-1 Saturday and Juventus hosted injury-depleted Udinese later with a chance to return to second place.
Elsewhere, Palermo and Catania played out a 1-1 draw in a tense Sicilian derby.
Giulio Migliaccio put Palermo ahead after four minutes and Jorge Martinez equalized for Catania in the 55th. A late goal from Catania's Giuseppe Mascara was ruled out for a questionable offside call.
Nico Pulzetti scored a 90th-minute winner in Livorno's 2-1 win over Genoa, Napoli and Lazio drew 0-0 and Atalanta beat last-place Siena 2-0 in what was probably Marco Baroni's last game as the Tuscan club's coach. Prospective replacement Walter Novellino attended the game.
In Milan, the Rossoneri took the lead six minutes in when Seedorf scored from the center of the area after Borriello had drawn Cagliari goalkeeper Federico Marchetti out of his goal.
Alessandro Matri equalized for Cagliari in the ninth minute when he was left alone by Milan defender Kakha Kaladze inside the area. With Cagliari dominating momentarily, the visitors went 2-1 up in the 30th with a goal from Andrea Lazzari, Milan's defense again having left a player unmarked inside the area.
Milan responded with two goals in the space of three minutes.
Borriello headed in the rebound after a Pato shot in the 38th and Pato then collected a pass from Ronaldinho before scoring with a precise shot into the top corner.
Ronaldinho made it 4-2 with a penalty in the 62nd, celebrating with his usual samba dance, and Cagliari made the San Siro crowd fret to the end with a goal from Nene following a counterattack in the 69th.
In the capital, Totti scored six minutes into his return, converting a penalty after Mirko Vucinic was dragged down inside the area.
Totti nearly scored again a few minutes later but Bari goalkeeper Jean-Francois Gillet deflected his shot off the post.
The Roma captain doubled the lead with a free kick through Bari's wall in the 14th minute, and completed the hat trick with a left-footed shot from a narrow angle in the 28th.
Bari pulled one back with an own goal by Roma defender Marco Andreolli following a corner in the 73rd.
Despite playing only eight of Roma's 13 games, Totti is the Serie A's joint top scorer with Udinese's Antonio Di Natale with nine goals each.
