Cristiano Ronaldo fluffed his lines in one of the great theatres of world football last night but, after his team-mates held firm to earn a goalless draw with Barcelona in the Nou Camp, the forward promised to atone for his third-minute penalty miss by scoring the goal on Tuesday that would take Manchester United to the Champions League final in Moscow next month.

It seemed that Ronaldo’s early aberration would come at a heavy price as Barcelona produced some beautiful football but, with Frank Rijkaard’s team lacking the penetration to match their approach work, United survived with a clean sheet.

Barcelona can progress with a win or a scoring draw at Old Trafford in the second leg of the semi-final but Ronaldo is confident that, despite his loss of nerve, as he lifted his penalty and shot wide, United will be in the final against Chelsea or Liverpool in Moscow on May 21.

“I didn’t change my style,” Ronaldo said. “I have scored a few penalties on that side of the goal before. It is no problem. I will score at Old Trafford. It was a tough game. Barcelona played very well and kept the ball a lot but we defended well. I think we’re going to win. Barcelona had a lot of the ball but we created more chances and that makes me feel very confident.”

Sir Alex Ferguson, three times a losing semi-finalist with United in the competition, was more cautious, preferring to say that his team have a “good” chance. He refused to criticise Ronaldo for the miss, saying that the penalty, awarded when the forward’s header was blocked by the hands of Gabriel Milito, may have come too early in the game for United.

“I would have backed Cristiano to score,” the United manager said. “He was a bit unlucky and maybe it came too early for us. But it was a professional performance from us. They had a little spell after half-time where Samuel Eto’o had a good chance but, other than that, I don’t think they had many opportunities.”

Ferguson’s satisfaction was increased by the way that a makeshift United defence coped in the absence of Nemanja Vidic, who had a stomach infection that forced him to spend Tuesday evening in hospital.

Vidic was taken to the nearby Hospital de Bellvitge for assessment on Tuesday afternoon, shortly after speaking at the pre-match press conference, and although a spokesman for the hospital said that his condition was “not serious”, Ferguson said that he feared that the Serbia defender would not be well enough to play in the much-hyped Barclays Premier League title “decider” away to Chelsea at lunchtime on Saturday.

“Vidic had some very severe stomach pains on Tuesday afternoon and we felt that the hospital was the best place for him to go,” Ferguson said. “We know that it was an infection, but we don’t know what kind. The only thing he has eaten for 36 hours is some soup during the afternoon. I don’t think he will be ready for Saturday, but we will give him every chance to be.”

Vidic watched the game at the hotel in the city centre, where, in a change of routine for Ferguson’s team, they returned after the match last night rather than fly straight back to Manchester. Instead, they will fly to London this afternoon to prepare for their important encounter with Chelsea, whom they could yet meet in Moscow on May 21.