Cristiano Ronaldo claims poor refereeing decisions denied Manchester United the chance to take more than a slender 1-0 lead to Arsenal.
Ronaldo claimed Danish referee Claus Bo Larsen "did not have best night" and two crucial offside calls denied United goals in the Champions League semi-final first-leg at Old Trafford.
TV replays showed Brazilian midfielder Anderson was onside when he was flagged, while Ryan Giggs, who went on to score, was a borderline decision.
Ronaldo said: "Two offsides are not offside and a few fouls he didn't give. It was not his best game.
"The first one Anderson was not offside and, with Giggsy, I'm not sure either. They are not great decisions but you have to respect the referees even if they were not brilliant - and just hope they will be better at Arsenal."
Ronaldo insisted United deserve to be the bookies' favourites to hold on to their European crown and believes they will triumph in next week's semi-final, second leg at the Emirates.
"We should be the favourites, we are the holders of the Champions League and we are full of confidence," said the Portuguese winger.
"It's going to be more difficult now Arsenal are at home but it's no problem to us as we are very experienced.
"We created so many chances that I believe we will score again at Arsenal next week.
"It was [Manuel] Almunia's night and he stopped a few goals and, when the goalkeeper is the best player on the pitch, it shows how difficult it is for other teams to play against us."
Ronaldo also paid tribute to Professional Footballers' Association Player of the Year Giggs, who came on as a second-half substitute to make his 800th appearance for United.
"He has had a fantastic season and 800 matches is an unbelievable achievement," added Ronaldo. "I hope to be like him one day. He is a fantastic player."
Meanwhile, Carlos Tevez, whose future at Old Trafford looks doubtful with his complicated loan deal due to expire at the end of the season, expressed his pleasure at his reception from the Old Trafford crowd last night.
Fans sang "Argentina, Argentina" and "Fergie, sign him up", and Tevez said: "It was great to hear the fans chanting my name. The crowd here are great to me and it means a lot.
"It is very important to get the 1-0 win but next week the game will be very difficult. It was very good for me to be in the starting line-up.
"We played well and wanted to score another goal but we must be happy with the way we played."