Juventus coach Massimiliano Allegri believes there is still more to come from his side after a double from Mario Mandzukic helped beat Serie A title rivals Napoli 3-1.

The Bianconeri maintained the perfect start to the new season and recorded a seventh straight league win, but fell behind at the Allianz Stadium after 10 minutes when Dries Mertens scored from close range.

Cristiano Ronaldo, though, soon inspired the start of an impressive comeback, his floated cross headed in by Mandzukic.

The Croatian frontman added another early in the second half after Ronaldo’s low shot had come back off the post.

Napoli full-back Mario Rui was sent off on the hour for collecting a second yellow card and defender Leonardo Bonucci added a late third following a corner.

Juventus are now some six points clear of Napoli, laying down an early Scudetto marker.

“We played well, against a good Napoli side, although we made a lot of tactical errors in the first period of the match,” Allegri said at a press conference.

“It was very good play from Cristiano Ronaldo on the first goal and from that moment we improved.

“It did annoy me, however, that we basically stopped playing when we were 11 against 10. We could have tried to get the ball forward, but we didn’t – plus they could well have equalised through Jose Callejon.”

Allegri added: “We still need to improve. We are still making errors of judgement.

“Let’s not forget that we’ve got a lot of clashes with our title rivals still to play – there are a certain number of games you need to win.”

Napoli boss Carlo Ancelotti lamented the decision to show Rui a red card after a challenge on Paulo Dybala midway through the second half.

“I do think the referee sent Mario Rui off a bit too easily,” Ancelotti said, quoted by the club website.

“I went over to speak to (Luca) Banti after the final whistle because I wanted to understand. He didn’t even blow the whistle the second time, then he gave a foul when he could have taken his time before making a decision.

“I’m not talking about the refereeing as a whole, but one rushed decision which affected the game.”

Ancelotti, though, felt his players had just lacked a cutting edge.

“We probably need a bit more nous, but it’s a long season and nothing has been decided. Just as we lost here, Juventus could lose when they come to the San Paolo,” he said.

“We will keep on doing the things we are doing because the team are playing very well.”

Meanwhile, Juventus chief executive Giuseppe Marotta confirmed after the match he would not be continuing in his role past the end of his current tenure on October 25 as the Turin club continue “an extensive renewal”.

Marotta said in a statement: “I’ve had eight wonderful years here, full of success, and Juventus will always remain in my heart.”