Felipe Caicedo and Ciro Immobile scored as Lazio beat Roma 3-0 in the capital-city derby on Saturday to revive their hopes of Champions League qualification from Serie A.
Simone Inzaghi's men ended their bitter rivals' eight-match unbeaten run in the league to move only three points behind Eusebio Di Francesco's fifth-placed team in the race for a top-four spot, with a game in hand.
Victory at the Stadio Olimpico for Lazio also pulled them within six points of fourth-placed Inter.
Inzaghi's decision to leave Immobile on the bench took less than 12 minutes to pay dividends as Joaquin Correa played in Caicedo, and the former Manchester City striker rounded visiting goalkeeper Robin Olsen before tapping in his fourth league goal of the season.
Roma were much improved after the interval, with Stephan El Shaarawy and Nicolo Zaniolo both bringing saves from Thomas Strakosha.
Lazio made their rivals pay 18 minutes from time, as Immobile scored his 16th goal of the campaign only eight minutes after coming on as a substitute.
The 29-year-old striker sent Correa running through on goal, with Federico Fazio outpaced and resorting to bringing down the forward, and Immobile squeezed the resulting penalty underneath Olsen.
There was further pain for Roma late on, as a wonderful team move from Lazio ended with midfielder Danilo Cataldi curling home an 89th-minute third goal.