Porto have taken advantage of their poor start to win their first match in a new season against Juventus in the Coppa Italia.
A penalty was controversially disallowed by referee Francesco Guarini for Juventus goalkeeper Gianluigi Buffon after the defender collided with the Italian international.
Guarini’s decision meant that Juventus were forced to play without goalkeeper Gianluca Mazzarri for the match, which was played at the Juventus Stadium.
Juventus won the game 2-0, scoring two goals from Gianluigiano Ravanelli and Mario Mandzukic in the opening half-hour.
Ravanelli had scored a penalty for Juventus in this match before being replaced by Luca Scocco, and was replaced by Matteo Darmian in the second half.
Mazzarrie then replaced Guarriello and scored in the 83rd minute to put Porto in control and they would have won it 3-2 had Mandzuka not been sent off for a late challenge with Guarati.
Juve captain Paulo Dybala had the best of the Juventus attack in the first half, scoring the only goal of the game, but it was Porto who scored their third to take the lead and continue their domination.
Porto went ahead through Alessandro Florenzi’s penalty in the 77th minute, with Mandzakic heading it into the far corner from the spot.
Juventas goalkeeper Darmio was booked for a second booking of the match in the 85th minute after a high challenge with Mazzaro, which resulted in an instant red card.
Maggio Chiellini added to Juventus’ woes by firing in a penalty in stoppage time to seal the win.
Portos head coach Marco Van Basten said: “This is a very difficult match.
We know Juventus are very good and we are not favourites, but we know we are playing in a big match and we need to be in the top five.”
The win will add to a difficult season for Juventus, who have lost five of their last six games.