Joaquin Correa ensured Lazio kept their hopes of Champions League qualification alive on Monday with a double in a 3-0 win over AC Milan while Napoli jumped up to third thanks to a 2-0 triumph at Torino.
Correa opened the scoring for Lazio with only a minute on the clock at the Stadio Olimpico in Rome and added the second five minutes after the break.
Ciro Immobile struck the third with three minutes left as Lazio moved five points off the Champions League spots with a game in hand on their rivals.
"This was like a final for us, the last chance to stay in with a shout for the top four... it was a clear and dominant victory," Lazio coach Simone Inzaghi told Sky Sport Italia.
Inzaghi's side sit sixth, behind AC Milan who are level on 66 points with Napoli and Juventus -- third and fourth respectively -- but have dropped down to fifth after their second straight league defeat.
They are 13 points behind leaders Inter Milan, who can win their first league title since 2010 on Saturday if they beat Crotone and second-placed Atalanta fail to win at Sassuolo on Sunday.
Stefano Pioli's Milan, who started the weekend in second place, could have been beaten by a larger margin as Manuel Lazzari was denied a goal just before the break by the tightest of VAR offside calls and Italy forward Immobile struck the post seven minutes before he scored his 18th league goal of the campaign.
Pioli was however left frustrated by Correa's second, which was given after a lengthy VAR check following what he felt was a foul from Lucas Leiva on Hakan Calhanoglu.
"I don't understand how it wasn't given as a foul on Calhanoglu, said Pioli.
"He looked at it again and from the replay you cannot say Leiva doesn't catch Calhanoglu and completely miss the ball."
Napoli moved into third thanks to first-half goals from Tiemoue Bakayoko and Victor Osimhen earlier on Monday.
They could have been further ahead at the break following a dominant opening period in which Piotr Zielinski hit the post and Matteo Politano was unlucky to see his deflected shot slide wide.
Lorenzo Insigne, playing his 300th Serie A match for Napoli, also hit the upright with a curling shot just before the hour mark.
They failed to add to their tally but ran out winners to put pressure on their rivals.
Torino meanwhile are staring at the prospect of relegation following the defeat, which leaves them hovering above the drop zone.
They sit 16th, level on 31 points with Benevento, who occupy the final relegation spot, and 17th-placed Cagliari who boosted their chances of survival with a 3-2 win over Roma on Sunday.