Juventus beat 10-man Udinese 4-0 to move back into second spot in Serie A on Sunday, while Luciano Spalletti's second spell in charge of Roma began with a 1-1 draw against bottom side Hellas Verona.
Paulo Dybala scored twice, including a 25th-minute penalty after Udinese defender Danilo was sent off for bringing down Mario Mandzukic. Dybala also provided two assists for Sami Khedira and Alex Sandro as Juventus dominated the first half.
With its 10th consecutive league win, Juventus moved two points behind Napoli after the Serie A leader's 3-1 win over Sassuolo on Saturday. Inter Milan, which drew at Atalanta on Saturday, was two points further back.
"There are still 18 games to go, we need to get a lot more wins to get to the right amount for the title," Juventus coach Massimiliano Allegri said. "Napoli is on an extraordinary run, it is the favorite at the moment, but the top five in the table all have the chance to win it."
Fiorentina can leapfrog above Inter with a win at AC Milan later. Roma is nine points behind Napoli.
"We didn't do very well, even if we tried to and created chances which we then didn't make the most of," Spalletti said. "It's a difficult result to accept, but there are things to take from it, like the great work rate and the disappointment of the team when they came back into the dressing room. We have to work."
Elsewhere, Lazio fought back from two goals down to draw 2-2 at Bologna after home defender Adam Masina was sent off, while relegation-threatened Carpi beat Sampdoria 2-1 for a second successive win.
Chievo Verona drew 1-1 against Empoli and Genoa beat 10-man Palermo 4-0 in the lunchtime kickoff.
Udinese had beaten Juventus on the opening day and was looking for a similar result to celebrate the inauguration of the Nuovo Stadio Friuli, where all 25,000 seats were sold out.
However, Juventus took the lead in the 15th minute when Dybala curled a free kick over the wall and matters grew worse three minutes later.
Udinese failed to clear a corner and Dybal nodded the ball across the six-yard box for an unmarked Khedira to head home.
Any hope Udinese had of rescuing something from the match evaporated in the 25th. Stephan Lichtsteiner sent Mandzukic clear and he was brought down by Danilo, who was duly sent off.
Dybala converted for his 11th goal of the season.
Alex Sandro netted his first in Serie A three minutes from halftime, firing into the far corner from the edge of the area to complete the embarrassing rout.
Udinese almost got a consolation in the second half but Juventus goalkeeper Gianluigi Buffon fingertipped Francesco Lodi's free kick onto the post.
Spalletti, who first coached Roma from 2005-09, returned to the club this week after Rudi Garcia was sacked following just one win in its last 10 matches in all competitions.
But Roma's struggles continued against Verona, which hasn't won a match all season.
Radja Nainggolan broke the deadlock four minutes from halftime with his first league goal of the season after a brilliant backheeled assist from Daniele de Rossi.
The goal came moments after Edin Dzeko had hit the post, prompting hope of a better second half for the hosts.
Both sides hit the woodwork after the break before Verona levelled just after the hour when Leandro Castan brought down Pawel Wszolek and Giampaolo Pazzini fired the resulting penalty in off the underside of the crossbar.
Dzeko should have won it for Roma in stoppages but headed over the bar from close range.