ROME, Dec 10 (Reuters) - AS Roma's challenge for the Serie A title suffered a setback when they lost 3-0 to city rivals Lazio on Sunday.
The result left Roma second on 32 points from 15 games, seven behind Inter Milan, who won 3-0 at Empoli in an earlier match.
Midfielder Cristian Ledesma put Lazio ahead with a superb long-range strike on the stroke of halftime.
Massimo Oddo doubled their advantage from the penalty spot shortly after the restart after Roma keeper Doni had upended Goran Pandev.
Massimo Mutarelli added a third with a close-range volley midway through the second half.
Serie A leaders Inter Milan beat Empoli 3-0 on Sunday to notch up their eighth league win in a row and match their best winning run in Italy's top flight.
The win, thanks to second-half goals by Hernan Crespo, Zlatan Ibrahimovic and Walter Samuel, equalled a club record that dates back to the 1939-40 season.
Inter have 39 points from 15 matches, seven points ahead of second-placed AS Roma, who take on city rivals Lazio in a later game (kickoff 1930 GMT).
Catania beat Udinese 1-0 to climb to fourth on 23 points, but AC Milan, who started the season with eight points deducted for their part in a match-fixing scandal, remain mired near the foot of the division after Alberto Gilardino missed a penalty in a 0-0 draw with Torino.
Inter lacked their usual fluency in the first half at Empoli's Castellani stadium.
The closest they came to taking the lead before the interval was when a short clearance from a free kick fell kindly for Santiago Solari to thump the ball into the side-netting.
In the 60th minute, however, Ibrahimovic headed a free kick off the bar and Crespo reacted quickly to turn the rebound into the roof of the net.
As Empoli pushed forward for an equaliser, they left themselves exposed at the back, opening up the space for Ibrahimovic to run at goal and curl Inter's second goal in off the post.
Defender Samuel wrapped up the result three minutes from time when he headed in a Nicolas Burdisso cross.
'We played an excellent match today,' said Inter coach Roberto Mancini, who identified his team's 4-3 win over Milan at the end of October as the result that gave his players the self-belief to extend their winning run.
'After winning the derby we were aware of what we were capable of if we stayed focused,' he said.
'Empoli were a tough side, but we only risked conceding a goal once. That's the mark of a great team.'
While Inter go from strength to strength, there seems no end to Milan's disappointing form. The Serie A giants lie 15th in the 20-team division with 13 points.
After watching his players lose 2-0 to Lille in the Champions League midweek, team coach Carlo Ancelotti had asked for an 'immediate reaction' against Torino.
Instead, it was another listless performance by Milan, who appeared to have saved themselves in the 77th minute when visiting defender Gabriele Cioffi tripped Gilardino to give away a penalty.
The Italy striker's spot kick struck the post, however, and Milan were lucky to come away with a point after Torino striker Roberto Muzzi twice hit the woodwork in the closing stages.