Defending champion Inter Milan gave a signal of intent as it crushed Roma 3-1 to move on top of Serie A on a miserable return to San Siro for former coach Jose Mourinho on Saturday.
Denzel Dumfries, Marcelo Brozović and Lautaro Martínez scored for Inter and Henrikh Mkhitaryan netted a late consolation.
Inter moved a point above AC Milan, which faces a tricky trip to Lazio on Sunday.
It was the third straight match in which Inter scored three, having done so at Spezia last weekend in the league and on Tuesday in the Italian Cup semifinal against Milan.
“I was very worried about this match because we’d given so much in the derby and we were up against another great team today," Inter coach Simone Inzaghi said. "We needed a first-rate performance and the lads were magnificent. This is a crucial win.”
Roma’s first loss in 12 league matches left it five points behind fourth-placed Juventus.
It was Mourinho’s first Serie A match at Inter as an opposing coach since he left the club in 2010 after steering it to the treble of the Italian league, Cup and Champions League. Inter beat Roma 3-0 in the Italian capital in December.
The Nerrazzurri also beat Mourinho's side 2-0 in the Italian Cup quarterfinals in February.
“I love Inter and Inter love me, but I want to win every game,” Mourinho said. "Now that we do not have to play against either Inter or Milan or Juve or Napoli again this season, then I can say that obviously I would be happy if Inter win the Scudetto.
"But before the game I want to win and I forget where I have been before. I love Inter but I love Roma and I love my job now. We get paid to win.”
Inter scored first when Dumfries ran onto a delightful through-ball from Hakan Çalhanoğlu and slotted it between the legs of the onrushing Roma goalkeeper Rui Patrício.
They doubled the lead five minutes from halftime with a splendid goal from Brozović, who cut inside and beat Chris Smalling before curling into the top right corner.
The match was all but over seven minutes after the break when Martínez was left unmarked to head in a corner from close range.
Despite the scoreline, Mourinho was still able to give a small smile and a wave when the Inter fans sang his name in the 72nd minute.
Roma pulled one back when Eldor Shomurodov cut the ball back for a fierce Mkhitaryan strike into the top right corner.