MILAN, Oct 26 (Reuters) - Last term's runners-up AS Roma slumped to their fifth defeat of the Serie A season when they lost 3-1 at new leaders Udinese on Sunday.
Italy forward Antonio Di Natale struck twice to ratchet up the pressure on Roma coach Luciano Spalletti, who made his name as boss of the Udine club.
Inter Milan are level with Udinese on 17 points from eight games after drawing 0-0 with Genoa in another drab home display.
Napoli are also on 17 after Sebastiano Siviglia's unlucky own goal secured a 1-0 victory at fast-sinking Lazio, who were early pacesetters but have now not won in three games.
AC Milan are a point behind after Kaka scooped home 10 minutes from time to seal a fortunate 1-0 win at Atalanta, who had troubled a shaky visiting defence.
Kaka's shot from Marco Borriello's pass went into the ground and bounced high into the net.
Roma, a point above the drop zone, have been hit by injury and suspension this season but the problems look to be far deeper and Spalletti could be in trouble if they lose to Sampdoria in Wednesday's fixtures.
A 4-0 thumping at home by Inter last weekend was followed by a 1-0 defeat by Chelsea in midweek despite a battling display.
They started poorly against confident Udinese, who beat Tottenham Hotspur in the UEFA Cup on Thursday, when Max Tonetto needlessly brought down Antonio Floro Flores to concede a 10th-minute penalty, although it may have been just outside the box.
Di Natale slotted home and striker Floro Flores added the second midway through the half with Roma looking ragged. Di Natale extended the lead after the break in another flowing move with Francesco Totti's late penalty useless for the away side.
"I probably made a mistake because everyone knows about the long balls Udinese play to their front three. We didn't react well to that," Spalletti told Sky television.
Inter, who sneaked a 1-0 home win over Anorthosis Famagusta in the Champions League on Wednesday, again struggled and apart from coach Jose Mourinho's new shorn haircut, their closest shave came when Maicon's cross deflected on to the bar.
Genoa also struck the woodwork and although they had Ivan Juric dismissed for a second booking, the visitors could easily have snatched victory.
Midtable Juventus, who had lost their last two matches in Serie A, beat Torino 1-0 in Saturday's Turin derby thanks to a third goal in a week from striker Amauri.