Cristiano Ronaldo wept tears of frustration after his Champions League debut for Juventus ended in a sending off against Valencia.
The Portuguese star had made a promising start to Wednesday's game in the Mestella stadium as he set up early opportunities for Mario Mandzukic and Sami Khedira before tangling in the penalty area with Valencia defender Jeison Murillo.
Ronaldo aimed a petulant kick at Colombian Murillo who fell to the ground instantly, with referee Felix Brych having no hesitation in showing him the red card after consulting his assistant official.
Ronaldo, so keen to make an early impression for Juve in the competition, sunk to the ground in disbelief with his head in his hands before trudging off with his eyes welling with tears.
Despite his dismissal, the Serie A champions won the Group H opener 2-0 thanks to a pair of Miralem Pjanic penalties either side of half time with Valencia seeing a late penalty by Daniel Parejo saved to cap a poor night for the Spanish side.
Ronaldo will miss the next game in the competition against Young Boys and could also be sidelined for both key matches against his old club Manchester United depending on how UEFA views the sending off and his dissent towards the referee.
Coach Massimiliano Allegri lamented the controversial decision. "It's very disappointing, we almost lost because of that and we will be without Ronaldo for the next game.
"VAR (Video Assistant Referee) could have helped the referee make the right decision," he said in barbed reference to lack of video technology in UEFA games.
It was the first time in 154 Champions League games that Ronaldo has seen red, but he has been sent off 11 times previously in his storied career.
After his summer move from Real Madrid, Ronaldo finally scored his first goals for the Old Lady at the weekend and looked set to add to his tally until his ignominious exit.
Manchester United, favored to contest top spot in the group with Juve, overcame a slow start on an artificial pitch in Switzerland to beat Young Boys 3-0 with Paul Pogba starring.
The French World Cup star scored the first with a stunning effort before adding a second from the spot.
Anthony Martial scored the third for Jose Mourinho's men in a comfortable victory.
Real impresses in opener
Reigning champion Real Madrid began its defense in the post-Ronaldo era with a 3-0 thumping of AS Roma in the Santiago Bernabeu stadium.
Isco put dominant Real ahead at halftime before in-form Gareth Bale added the second from a fine pass by Luka Modric with Mariano capping a fine performance against last season's semifinalist with a curling shot for the third.
Big shock of the night came with the 2-1 home defeat for English Premier League winner Manchester City against Lyon.
Pep Guardiola's team fell 2-0 behind at halftime as Maxwel Cornet and the excellent Nabil Fekir scored for the French visitor.
Leroy Sane came off the bench for City in the second half to set up Bernardo Silva for a goal, but that was the extent of the comeback.
Bayern Munich made no mistake in Lisbon against Benfica with Renato Sanches scoring against his old club and earning a standing ovation for his effort.
Robert Lewandowski had grabbed the opener from a cross by Franck Ribery in a 2-0 win for Bayern.