Mirko Vucinic scored two second-half goals as AS Roma rallied to beat Lazio 2-1 in a fractious derby Sunday to reclaim the Serie A lead after Inter Milan won on Friday.
Tommaso Rocchi put Lazio ahead in the 14th minute at the Stadio Olimpico but Sergio Floccari saw his penalty saved by Roma goalkeeper Julio Sergio to prevent the host going 2-0 ahead in the 47th.
Vucinic equalized from the spot eight minutes into the second half before the Montenegro forward smashed a free kick through a hole in Lazio's wall 10 minutes later for the winner.
"We definitely played better in the second half, and the turning point was certainly the penalty blocked by (Julio Sergio)," Roma coach Claudio Ranieri said.
With four rounds remaining, Roma leads with 71 points, one ahead of Inter, which beat 10-man Juventus 2-0. AC Milan are seven points off the lead after being beaten 2-1 by Sampdoria.
Roma, which trailed Inter by 14 points in October, extended its unbeaten run to 24 games, with 18 wins and six draws. The Giallorossi have won their last six matches.
"I think winning the derby is the greatest thing that exists in football," Vucinic said. "We were under pressure for two days and I think tonight we really showed we're a great club."
The derby loss left Lazio only three points above the relegation zone.
Earlier, Giampaolo Pazzini scored in added time for Sampdoria as it beat 10-man Milan to put a serious dent in the Rossoneri's title chances.
"Mathematically, anything is still possible. But this result certainly hurts," Milan coach Leonardo said.
Also Sunday, it was: Atalanta 2, Fiorentina 1; Bari 1, Napoli 2; Cagliari 2, Palermo 2; Catania 2, Siena 2; Parma 2, Genoa 3 and Udinese 1, Bologna 1.
Sampdoria's victory moved the Genoa-based team into fourth place, which is the final Champions League berth.
Sampdoria has 57 points while Palermo, which needed late goals from Fabrizio Miccoli and Abel Hernandez to draw at Cagliari, dropped to fifth with 55. Napoli, which scored two goals through Ezequiel Lavezzi against Bari, has 52 points. Juventus is seventh with 51.
Italy forward Antonio Di Natale scored his league-best 24th goal in added time to secure a draw for Udinese against Bologna.
Before the Rome derby, police had to intervene when fans threw heavy-grade firecrackers at each other ahead of kickoff, and the small crackers continued to explode throughout the match. The start of the match had already been brought forward two hours due to security concerns.
In the opening minutes, Roma forward Luca Toni kicked the forehead of Guglielmo Stendardo, forcing the Lazio defender to be taken off on a stretcher for medical attention with blood streaming down his face.
Rocchi's goal came from the first significant scoring chance for either side and it was his fifth goal in a Rome derby. The Lazio captain ran onto a perfectly placed through ball from Cristian Ledesma before beating Julio Sergio.
Roma struggled in attack throughout the first half and a long-range free kick from Norway international John Arne Riise smacked into Lazio's wall in the 23rd.
A minute later at the other end, Rocchi appealed for a penalty but the referee ruled that contact from defender Nicolas Burdisso was minimal.
Lazio coach Edy Reja, who took over for Davide Ballardini in February, used a 3-5-2 lineup, and his packed midfield created problems for Roma. Claudio Ranieri's side resorted to booting long balls toward 1.92-meter (6-foot-4) forward Luca Toni, but Lazio's defense prevented Toni from turning and shooting.
To start the second half, Ranieri made a bold decision to remove ineffective captain Francesco Totti and midfielder Daniele De Rossi - Roma's two most emblematic players and both Rome natives - in favor of French forward Jeremy Menez and attack-minded midfielder Rodrigo Taddei.
"The derby is too emotional for them, and they weren't playing like they usually do," said Ranieri, who is also a Roman native. "They know I'm always trying to do what's best for Roma, and that's what we all want."
But Roma should have fallen further behind 45 seconds after the restart when Marco Cassetti was adjudged to have tripped Aleksandar Kolarov in the area. Floccari's penalty was aimed toward the center of the goal, and Julio Sergio kept the shot out with his feet after diving to his right.
A few minutes later, Kolarov tripped Taddei, setting up Vucinic's penalty and re-energizing Roma.
Lazio ended the match with 10 men when Ledesma was sent off for mocking the referee in added time.
Milan had gone ahead in the 20th minute with a goal from Marco Borriello, but Antonio Cassano equalized with a penalty in the 54th after Milan defender Daniele Bonera was sent off for fouling the Sampdoria forward.
Borriello scored with a header from a corner, his 14th goal of the season boosting his chances of making Italy's World Cup squad. He did, however, pick up a yellow card that will keep him out of next week's match against Palermo.
A couple of Serie A clubs took longer than usual to travel to Sunday's games due to the volcanic ash plume shutting down aviation in northern Italy.
For its game against Catania, Siena had to travel part of the way to Sicily by bus, then got a flight from Rome. Fiorentina took a train to Milan, then made its way to Bergamo by bus.
