Cristiano Ronaldo struck twice, including a thunderous 25-yard drive, as Italian champions Juventus surged seven points clear in Serie A on Saturday following a battling 2-1 victory at Empoli.

Empoli, without a win since the opening weekend of the season, grabbed a 28th-minute lead at the Stadio Carlo Castellani as Francesco Caputo curled home following a lung-busting run by Afriyie Acquah.

But Juventus turned to their 100-million-euro man Ronaldo in the second half, as the Portugal forward equalised from the spot before blasting home a magnificent second to secure a ninth win in 10 Serie A matches for Massimiliano Allegri's team.

"It was a very complicated game. We knew it would be difficult, especially after a Champions League tie and we were a bit tired," Ronaldo told Sky Sport Italia.

"We stayed in the game, increased our possession, created more chances after the break and in the end deserved the victory.

"I don't remember the goal very well, I'll have to watch it again! It all happened very quickly, but I felt confident and I went for the goal."

After Caputo's opener, the hosts appealed for a penalty when Miha Zajc's shot glanced the arm of Leonardo Bonucci as he attempted to charge down the attempt, but the referee opted against punishing the Italy defender after reviewing the incident on video.

Empoli goalkeeper Ivan Provedel pulled off two spectacular saves in quick succession to thwart Alex Sandro and Miralem Pjanic early in the second half, as Juventus -- who beat Manchester United 1-0 at Old Trafford in midweek -- saw their unbeaten record come under threat.

Provedel flung himself in front of a firmly-hit effort by Sandro from close range, and then sprang acrobatically to his right to touch a Pjanic drive onto the crossbar as Empoli failed to clear after the initial attack.

But Juve hit back when Paulo Dybala pinched the ball off a dallying Ismael Bennacer in the Empoli box, drawing a penalty as the Algeria midfielder proceeded to bundle over the Argentine.

Ronaldo sent Provedel the wrong way from the spot to score for the third league game running and bring Juve level on 54 minutes, as the turmoil of rape allegations do not appear to be unsettling the Portuguese forward on the pitch.

After last weekend's 1-1 draw with Genoa, Ronaldo completed a much more successful week for Juve as he unleashed an unstoppable shot into the top left corner 20 minutes from time.