Roma move closer to Serie A summit after derby win
Eusebio Di Francesco's side moved to third in Serie A level on 30 points with Inter Milan ahead of Napoli's clash later with AC Milan after a hard-fought match decided by two goals in four second-half minutes from Diego Perotti and Radja Nainggolan.
'We showed great spirit, we are in wonderful form," said goalscorer Nainggolan.
The Belgium international was a doubt for the derby after picking up a groin injury during the international break but was the star of the show for Roma in midfield.
"I always want to help my teammates and I gave my all to be ready to play, as this is the kind of match you cannot miss."
Roma's fifth straight win saw them leapfrog Lazio, who drop down to fifth on 28 points after the derby defeat, ahead of Wednesday's trip to Atletico Madrid, where they could qualify for the Champions League knockout stages with a match to spare.
'This is a Roma side that is improving and has great belief," said coach Eusebio Di Francesco. "We've already turned our attentions to the game with Atletico Madrid.
"We want to stay up at the top for as long as possible and I think we've got the right mentality to do just that."
Dominant Roma looked set for a comprehensive victory when Perotti slotted home a 49th minute penalty and Belgium midfielder Nainggolan drilled home a fine low strike four minutes later.
However a Kostas Manolas handball, initially missed by referee Gianluca Rocchi but picked by the video assistant referee after protests from Lazio players, gave the away side a lifeline from the spot.
Ciro Immobile tucked away the penalty in the 72nd minute to make it 15 goals for the season.
Lazio pressed for an equaliser but Roma held out for a nervy three points that strengthened their claims to be a contender to Juventus' Serie A crown.