Paulo Dybala converted two penalties in the second half to rally Juventus to a 3-1 win in their Coppa Italia semifinal first leg, and Giuntoli was angered by both decisions from referee Paolo Valeri.

The first penalty was given in the opening minute after the break, when Valeri ruled that Napoli's Kalidou Koulibaly fouled Dybala.

The second was more debatable after Pepe Reina appeared to get a touch to the ball before bringing down Juan Cuadrado. Making matters worse, Napoli had just been denied their own penalty shouts for a foul on Raul Albiol at the other end.

Giuntoli told Rai Sport: "We thought it important to publicly thank the lads for their performance and to say we emerge defeated by two decisions that were not debatable, but shameful and damaging to all of Italian football.

"On the first penalty, Dybala knocks the ball on and seeks contact for the penalty. I thought the first one was frankly more of a spot kick, but after watching the replay this one isn't right either. The striker goes looking for the contact.

"On the second Reina gets the ball, then he certainly cannot disappear and thus he contacts the player too.

"What's more, that happened after a penalty was not given to us, considering that two of them knocked down one of our players. The decisions were shameful."

Reina also expressed frustration with the penalties, which allowed Juventus to overturn Napoli's fine first half in which the goalkeeper made a number of excellent saves.

"We had a good first half, made Juve split apart and did our work," Reina said. "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 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."

Juventus coach Massimiliano Allegri said Juventus were good value for their win in spite of the decisions.

"I don't want to give any verdict on referees. From the pitch they both looked like penalties, then I don't know," Allegri said.

"I think the Juventus performance cannot be reduced to just penalties. We must look beyond these things."

Allegri was also pleased with how his side responded to falling behind in the first half, saying:  "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.

"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."