Inter beat Livorno 4-1 at the San Siro to get a confidence boost ahead of Saturday's derby clash with Milan.
Palermo came from behind to beat Messina 2-1 in their Sicilian derby, David Di Michele getting the winner from the penalty spot for the home side.
Inter and Palermo are joint leaders on 18 points while third-placed AS Roma, held 2-2 at home by lowly Ascoli, trail by four points.
Milan, struggling in mid-table after beginning the season with a -8 point penalty imposed by a sports tribunal, beat Chievo thanks to a 25-metre drive by Czech midfielder Marek Jankulovski.
Inter went ahead in the second minute through a strange own goal by Livorno's French defender Marc Pfertzel who, under no pressure, inexplicably put through his own net from five metres.
Italy defender Marco Materazzi then made it 2-0 with a fine header from an Alvaro Recoba corner after 13 minutes.
Cristiano Lucarelli pulled one back for the visitors with a 70th minute header but a minute later, after skilful dribbling by Serbian Dejan Stankovic, Swede Zlatan Ibrahimovic made it 3-1.
Argentine Julio Ricardo Cruz completed the win for Inter with a header from a Luis Figo corner.
WAKE-UP CALL
Palermo went into their derby on a high after Sunday's impressive win over Milan at the San Siro but soon received a sharp wake-up call from Messina.
In-form striker Christian Rigano headed Messina in front with his sixth goal of the campaign after seven minutes but Palermo fought back with a Cristian Zaccardo header from a corner in the 25th.
David Di Michele then got the winner for Francesco Guidolin's side from the penalty spot four minutes from the break after he was brought down inside the area.
Marco Delvecchio, a member of Roma's 2001 title-winning side, scored against his old club to give struggling Ascoli the lead after 22 minutes at the Olympic stadium.
Roma drew level with a fierce drive from captain Francesco Totti five minutes after the restart and Vincenzo Montella then had an effort disallowed for offside.
Croatian striker Sasa Bjelanovic headed battling Ascoli back in front before Totti had a harshly-awarded penalty saved by Gianluca Pagliuca -- the 40-year-old keeper pushing the ball up against the underside of the bar.
However, Roma got a late reprieve with a last minute tap-in by Philippe Mexes after Pagliuca parried out a Totti free kick.
