AS Roma pounced on two dreadful Lazio mistakes to claim a 2-0 Serie A victory in a hot-tempered derby boycotted by their own supporters on Sunday.
Lazio's Wallace gifted Roma the lead in the 64th minute when he tried to dribble his way out of defence but was dispossessed by Kevin Strootman who chipped the ball over helpless goalkeeper Federico Marchetti.
There was a scuffle involving players and officials from both teams after the goal, sparked when Strootman squirted water at Lazio substitute Danilo Cataldi who grabbed the Dutchman's shirt by the collar.
Strootman was booked and Cataldi shown a red card.
Roma doubled their advantage in the 77th minute when Radja Nainggolan caught Marchetti napping with a low shot from 35 metres that bounced twice as it entered the net at his unguarded near post.
There was also controversy in the first half when Roma's Bruno Peres appeared to be tripped on the edge of the penalty area by Lucas Biglia.
The referee initially awarded a free kick to Roma before pointing to the penalty spot. He then changed his mind again, reverting to his first decision.
Lazio, technically the home side in the Stadio Olimpico, have not won any of their last seven meetings against Roma, a run going back to the 2013 Italian Cup final.
The Curva Sud area was empty as Roma's hardcore supporters continued a long-running stayaway campaign in protest at security measures they say have destroyed their fan culture.
Roma stayed second in Serie A on 32 points, level with AC Milan and four behind leaders Juventus. Napoli, Lazio and Atalanta are eight points off the pace.
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AC Milan forward Gianluca Lapadula celebrates scoring the winner against Crotone at San Siro AFP
Milan needed a late goal from Gianluca Lapadula to beat second from bottom Crotone 2-1 after M'baye Niang had earlier missed a penalty for the home side.
Diego Falcinelli gave visiting Crotone a 26th-minute lead and Mario Pasalic headed the equaliser four minutes before the break, his first goal since joining Milan on loan from Chelsea in the close season.
Milan were awarded their penalty early in the second half and Niang won an argument with Lapadula over who should take it, only for Alex Cordaz to save his shot brilliantly.
Lapadula grabbed the winner in the 86th minute but was booked for his exuberant celebration.
Bottom club Palermo, where Eugenio Corini made his debut as their third coach of the season, slumped to their eighth successive league defeat when they lost 2-1 at Fiorentina, Khouma Babacar heading the winner deep into stoppage time.
Two first-half penalties, the first from Lorenzo Pellegrini and the second by Federico Ricci, helped Sassuolo to a 3-0 victory over Empoli that ended a nine-match winless run in all competitions.
Antonino Ragusa netted the third early in the second half.
Sampdoria beat Torino 2-0 with second-half goals from Edgar Barreto and Patrik Schick while Gianluca Caprari scored in stoppage time to give lowly Pescara a 1-1 draw at home to Cagliari.
The Sardinians went ahead through Marco Borriello in the 24th minute but had Davide Di Gennaro sent off 10 minutes later.
AC Milan 2
(Pasalic 41, Lapadula 86) Crotone 1
Lazio 0 Roma 2
(Strootman 64, Nainggolan 77)
(Caprari 90+2) Cagliari 1
(Barreto 51, Schick 90+5) Torino 0
(Pellegrini 22-P, Ricci 36-P, Ragusa 53) Empoli 0
(Bernardeschi 33-P, Babacar 90+3) Palermo 1
P W D L GD Pts
15 12 0 3 19 36
15 10 2 3 19 32
15 10 2 3 12 32
15 8 4 3 12 28
15 8 4 3 11 28
15 9 1 5 7 28