Mario Mandzukic scored twice as Juventus came from behind to beat 10-man Napoli 3-1 and maintain their perfect start to the new season with a seventh straight Serie A win.

Napoli had started the day in second place and were looking to draw level with the Bianconeri, who opened their Champions League campaign with victory at Valencia.

The visitors took an early lead at the Allianz Stadium after 10 minutes through Dries Mertens.

Juventus, though, were soon level when Mandzukic powered in a header from Cristiano Ronaldo’s floated cross.

The Croatian frontman knocked in a second shortly after the restart when Ronaldo’s low shot hit the post.

Napoli saw full-back Mario Rui sent off on the hour for a second yellow card and defender Leonardo Bonucci added a late third for the hosts, guiding in Ronaldo’s header at the far post from a corner.

It had earlier been such a positive start by Carlo Ancelotti’s men, with Piotr Zielinski seeing his left-foot shot crash against the post.

The visitors then took a deserved lead in the 10th minute.

Brazilian midfielder Allan latched onto a stray pass from Bonucci and picked out Jose Callejon on the right, with the ball then played back across goal for Mertens to tap in.

Juventus were level in the 26th minute. Ronaldo stood up a cross from the left through the six-yard box for Mandzukic to power a header past David Ospina.

Napoli were then almost behind when Ronaldo’s angled free-kick from the corner of the penalty area was beaten away by Ospina at the near post. Miralem Pjanic’s follow-up, though, was blocked at point-blank range by Marek Hamsik.

Juventus continued their momentum after the restart and took the lead after 49 minutes.

Again, Ronaldo was the instigator as his low shot flew against the bottom of the post with Ospina beaten and bounced back across into the path of Mandzukic, who knocked it into an empty net.

Napoli’s hopes of getting back into the match suffered a blow just before the hour when Rui was sent off for a second caution after clattering into Paulo Dybala.

Tempers boiled over, with the referee showing further yellow cards to both Napoli defender Elseid Hysaj and Bonucci for their part in a scuffle before play could resume.

Napoli could have snatched an equaliser when substitute Arkadiusz Milik picked out Callejon, but his effort was pushed away by Juventus goalkeeper Wojciech Szczesny.

With 14 minutes left, Juventus made sure of the points and an early statement of intent in the early-season Scudetto showdown.

A corner was swung across from the right, which Ronaldo glanced down towards the bottom corner and Bonucci stabbed it in at the far post.

Ronaldo had a late one-on-one chance blocked before then seeing a goal correctly ruled out for offside.