Paulo Dybala scored his first Serie A goal of the season to give Roma a 1-0 victory at Sassuolo on Sunday to lift them level on points with leaders Napoli.
After 16 minutes Dybala set up Bryan Cristante for a shot. When Arijanet Muric saved, Dybala pounced to put the rebound into the empty net.
It was the Argentinian's 130th Serie A goal but his first from open play since last December.
"These are three important points," said Dybala, whose team are hoping to deliver a first Scudetto for Roma since 2001.
"We knew we could move into first place before this match, but we're not getting carried away. The championship is still very long."
Under Gian Piero Gasperini, who took over in July, Roma have become stingy in defence but are struggling to score.
In eight games they have conceded three goals – two fewer than any other team – while scoring only eight.
Roma sit second behind reigning champions Napoli, who beat fourth-placed Inter Milan 3-1 on Saturday, on goal difference.
However, if two teams are level on points at the top of the table at the end of the season, the title will be decided in a play-off.
All four of Roma's defeats this season have come at home, including a loss to Viktoria Plzen in the Europa League on Thursday and against Inter Milan in Serie A last Saturday.
"I'm very satisfied because the team reacted well after two defeats this week," said Gasperini.
"The priority now is to win again at home. We have to reward our fans. At home, we have to be more effective."
AC Milan, held to a 2-2 draw by Pisa on Friday at the San Siro, dropped to third, a point behind.
JUVE BEATEN AGAIN
Lazio extended Juventus' winless streak in all competitions to eight matches with a 1-0 victory at the Stadio Olimpico.
Juventus fell behind in just the ninth minute when Jonathan David carelessly gave the ball away inside his own half, before Toma Basic drilled in a deflected shot from outside the box.
The visitors thought they should have been awarded a penalty on the hour mark when Mario Gila appeared to trip Francisco Conceicao, but their appeals were in vain.
Lazio managed to hold on to an important three points, helped by an excellent save from Ivan Provedel to keep out a Khephren Thuram header with 15 minutes left.
The capital club moved into 10th, one point behind their beaten opponents.
"We are of course disappointed, we feel terrible, but there is always something missing in our matches. We are all responsible for this situation," said Juve coach Igor Tudor, insisting he is "not worried about his future".
Elsewhere, Fiorentina remained winless despite fighting back to rescue a 2-2 home draw with Bologna.
Goals from Santiago Castro and Nicolo Cambiaghi put Bologna on track to climb to fourth place and close within two points of the leaders.
But Albert Gudmundsson pulled one back from the penalty spot for La Viola, before Bologna's Emil Holm was sent off for a second booking.
Fiorentina took advantage to rescue a draw as Moise Kean netted another spot-kick in the third minute of added time.
Stefano Pioli's Fiorentina still have just four points from their opening eight league games and are languishing in 18th place.
Torino made it back-to-back wins after downing Napoli last week with a 2-1 victory against Genoa.
