Massimiliano Allegri believes there is still more to come from Juventus, with the coach demanding greater intensity from his side despite the Serie A leaders putting one foot in the Coppa Italia final with Tuesday's 3-1 first-leg defeat of Napoli.

The holders came from behind to take control of the tie, with a pair of controversial Paulo Dybala penalties and a Gonzalo Higuain goal against his old club putting Juve in a dominant position after they recovered from Jose Callejon's superbly crafted opener.

Juve are now in a strong position to win the league and cup double for the third year in a row, but Allegri felt his side were below-par in the first half, when they fell behind to Napoli for the first time at Juventus Stadium, while using a back three.

"In the first half more than having the wrong system, we made too many mistakes in our passing, but nonetheless had plenty of chances and allowed Napoli very little," Allegri told Rai Sport.

"The first half was bad on a technical level, the second was much better. I don't think we played badly with three at the back, we must made too many mistakes in our passing, but it went very well after the break.

"I have to compliment the entire squad, as they played a fine second half and managed to come back despite going a goal down.

"Napoli are always dangerous and we finished the game on a high, so this bodes well for the future. I think we can improve a great deal in terms of intensity.

"I particularly wish to compliment Miralem Pjanic, someone who has really improved."

Napoli were left to lament arguable penalty decisions made by referee Paulo Valeri, with goalkeeper Pepe Reina particularly frustrated by the official's calls, which included a spot-kick against him for bringing down Juan Cuadrado despite getting a touch on the ball.

"We had a good first half, made Juve split apart and did our work," Reina told Rai Sport. "With the second-half incidents, everything changed. The result changed because of the referee's decisions. That is all.

"What am I supposed to do, disappear? If a player gets the ball, he gets the ball, end of story. Are players not supposed to touch the ball anymore? In my view, I moved the ball, so he either had to jump or get out of the way. In my view, people aren't talking enough about the penalty on [Raul] Albiol.

"That incident was definitely more of a penalty than the Cuadrado one. We must certainly learn and improve and play a better second half, but I am absolutely furious. It's not fair. The final result was changed by the refereeing decisions. That is all you can say."