Juventus beat a disorganised AC Milan 4-2 in an enthralling Serie A encounter on Sunday to go clear in second place.
Striker Amauri scored twice to put Juve six points behind leaders Inter Milan, who earlier defeated bottom side Chievo 4-2, while Milan now trail their city rivals by nine after 16 matches.
Driving rain made conditions in Turin difficult but Italy's two most successful teams of the last 20 years still put on a hugely enjoyable show.
Alessandro Del Piero gave the hosts the lead with a 16th-minute penalty after being brought down by Marek Jankulovski, who touched the ball with his sliding tackle.
Milan, without the injured Kaka, levelled on half an hour when Kakha Kaladze released Ronaldinho and the Brazilian set up compatriot Alexandre Pato to crash home from close range.
Juve went in front again just four minutes later when defender Giorgio Chiellini found space to head in a corner and Brazilian-born Amauri exposed more loose Milan defending when he nodded in Paolo De Ceglie's excellent cross.
The visitors introduced Andriy Shevchenko at halftime and they pulled one back on 56 minutes through Massimo Ambrosini's deflected shot but their hopes ended when former Juve defender Gianluca Zambrotta was sent off for a second booking.
Amauri then squeezed in his second in the 69th minute to leave Milan in joint third with Napoli, who beat Lecce 3-0 on Saturday.
Zlatan Ibrahimovic scored twice in the last 11 minutes to seal a nervous win for Inter at home to Chievo on a day packed with goals and comebacks.
The champions were cruising at 2-0 following quality strikes from Maxwell and Dejan Stankovic but the visitors hauled themselves level through Sergio Pellissier and Simone Bentivoglio before Swede Ibrahimovic was again Inter's saviour.
"At 2-0 everyone in the stadium and on the pitch thought the game was over. It is a lesson," Inter coach Jose Mourinho said.
AS Roma triumphed in another fluctuating game, Mirko Vucinic netting the stoppage-time winner in a 3-2 victory over Cagliari.
Luciano Spalletti's side, who had a terrible start to the season, have now won five league games on the bounce to rise up to mid-table.
In-form Francesco Totti lashed in the opener for the hosts but Daniele Conti's free kick and a superb strike from Jeda put the Sardinians ahead. Simone Perrotta's overhead kick and a scruffy finish from Vucinic helped Roma roar back.
Lazio are a point ahead of their city rivals after coming back from 3-0 down to draw 3-3 at Udinese, who folded like so often in recent weeks having been early season pacesetters.