Gianluca Mancini fired Roma into Serie A's Champions League places with the only goal in Sunday's 1-0 win over Juventus, while Inter beat Lecce to retain second place.
Italy defender Mancini let rip with a perfectly-struck shot six minutes after halftime of a tight contest in Rome, lifting Jose Mourinho's team to fourth, 12 points ahead of Juve who played the final moments a man down after substitute Moise Kean booted Mancini.
Roma are ahead of AC Milan on goal difference following the champions' defeat at Fiorentina on Saturday night and three points behind Inter.
Champions League football looks increasingly unlikely for Juve, who hit the woodwork three times, unless their 15-point penalty for illicit transfer activity is overturned on appeal.
Mourinho was in the Roma dugout after his two-match ban for a row with officials at Cremonese was suspended.
The Portuguese coach is not famed for expansive football and the teams served up a dour spectacle in the opening half, which would have ended with Juve ahead had Rui Patricio not pulled off a magnificent save to tip Adrien Rabiot's close-range header onto the post.
All the hosts had mustered up to that point was a speculative shot from former Juve star Paulo Dybala, playing up front on his own with Tammy Abraham on the bench. The effort was easily saved by Wojciech Szczesny.
But Mancini clattered Roma ahead just as Juve looked to be gaining a foothold. He was left alone to shoot from just outside the area and unleashed a low drive at which Szczesny could only grasp in vain.
Juan Cuadrado almost immediately smacked a free-kick against the post before Szczesny made a brilliant reaction stop to deny Chris Smalling in the 75th minute.
Mancini almost undid his good work when he headed against his own post, but was key to Juve finishing with 10 men when, after a tussle with Kean in the final minute, he was kicked by the Juve forward who was sent off seconds after being brought on for Cuadrado.
INTER HOLD SECOND SPOT
Goals in each half from Henrikh Mkhitaryan and Lautaro Martinez gave Inter the points against promoted Lecce and slightly closed the giant gap between them and Napoli to 15 points.
However, the league title is still a distant hope despite Napoli's shock home defeat to Lazio on Friday night, Inter's main concern being Champions League football next season.
"We were focused and keep going, and that is how you win games," said coach Simone Inzaghi.
"Lecce are aggressive and press hard, we really had to move off the ball to create space. We did really well."
Lecce, in 15th, have been a thorn in the side of Italy's big boys this season but offered very little at a subdued San Siro.
Defeat didn't have much impact on Lecce's survival hopes as they are nine points above Verona, who are just inside the relegation zone and drew 0-0 with fellow strugglers Spezia earlier on Sunday.
Verona are three points behind a Spezia team hovering dangerously above the drop zone and six ahead of troubled bottom side Sampdoria.
Without a win in nine and weighed down by financial problems, Samp only managed a goalless draw with Salernitana in Sunday's early match.
Salernitana are also trying to beat the drop and the uneventful stalemate in Genoa kept Paulo Sousa's side seven points ahead of Verona.