Cristiano Ronaldo had a penalty saved but it mattered little as Juventus beat last-placed Chievo Verona 3-0 to extend its advantage in Serie A on Monday.
Douglas Costa and Emre Can scored first-half goals and Daniele Rugani added the last late as league leader Juventus restored its nine-point advantage over second-placed Napoli, which beat Lazio 2-1 on Sunday.
It was a bad start to what will already be a difficult week for Ronaldo. He makes an unwanted trip back to Madrid for an expected guilty plea to tax fraud related to his time at Real Madrid.
"There are more important penalties ... he missed a similar one this morning, too, in training," Juventus coach Massimiliano Allegri said. "However, what's important is the team won in the end.
"Ronaldo was betrayed in the first half by too much desire to score a goal. Things went better for him in the second half, when he was trying to do easier things."
Ronaldo is expected to appear before a judge in Madrid on Tuesday and receive a suspended two-year sentence as part of a deal struck with Spain's state prosecutor and tax authorities last year. The agreement will cost him nearly 19 million euros ($21.6 million) in fines.
Separately, Ronaldo is facing a rape allegation in the United States.
Kathryn Mayorga filed a civil lawsuit in Nevada in September claiming Ronaldo raped her in his Las Vegas hotel room in 2009. Police reopened an investigation into the allegation at her request. Ronaldo has denied any wrongdoing.
Ronaldo has been playing and scoring regularly since the rape allegation emerged but the Portugal superstar appeared distracted on Monday as he uncharacteristically missed decent opportunities.
His penalty was turned around the post by veteran goalkeeper Stefano Sorrentino at full stretch. Sorrentino, who was accidentally knocked unconscious by Ronaldo in the opening round of matches, turns 40 in March.
There was some perceived justice in this for Chievo, which felt the penalty was harsh as Mattia Bani was trying to get out of the way of the Douglas Costa shot when it hit his hand.
Juventus was already in control by that point as Douglas Costa scored in the 13th minute with a powerful 20-yard effort into the bottom right corner.
On halftime, Paulo Dybala was surrounded by Chievo players but managed to thread the ball to Emre Can to score his first goal for Juventus since his offseason move from Liverpool.
Chievo, which is nine points from safety, played well but abysmal defending gifted Juventus a third six minutes from time as Rugani was allowed a free header on Federico Bernardeschi's free kick.
AC Milan moved back into the Champions League qualifying spots with a 2-0 victory at Genoa.
Fabio Borini and Suso scored in the second half to put Milan in fourth place. Suso did not celebrate scoring against his former team.
Milan also got help from goalkeeper Gianluigi Donnarumma. He made a spectacular double save before the goals, first denying Miguel Veloso and then smothering Daniel Bessa's follow-up from close range.