Sir Alex Ferguson confirmed local police had to step in after a fan with a laser targeted his Manchester United players in Istanbul.
United opened their quest to reach a third successive Champions League final by beating Besiktas 1-0.
Paul Scholes nodded home the winner 13 minutes from time, sealing a game where the visitors were on top without managing to make their superiority tell.
But the game was not without incident, with Ferguson revealing Jonny Evans was among those picked out by the idiotic fan.
"It was in the first half, although thankfully the police did something about it,'' said the United boss. "They managed to get the culprit, which is good because I noticed it particularly on Jonny Evans. It seemed to be on him all the time.''
Ferguson was also alerted to a security problem behind his dug-out, although he was eager not to make an issue of that. "Someone mentioned it to me, but I never saw anything,'' he said. I do know the fans made the loudest noise I have ever heard. They never stopped the whole night.''
United managed to overcome that handicap, with Scholes making the headlines for all the right reasons after his red card at Tottenham on Saturday. The veteran midfielder responded quickest after Nani saw his blistering shot saved by Hakan Arikan.
"Nani was a bit unlucky not to score himself but Paul Scholes did what he does best. It was a typical Paul Scholes goal,'' said Ferguson.
The United manager was delighted with his team's overall display, particularly Antonio Valencia, who was making his Champions League debut following his £17 million summer arrival from Wigan.
"Antonio was always a threat,'' said Ferguson. "He got to the byline so many times and really we should have done better. He has got the potential to be a really good player. He is powerful and strong, with a lot of enthusiasm. He is very quick, with good balance and in a year's time he will have developed more parts of his game.''
One player who did not look best pleased to have his evening curtailed was Wayne Rooney.
Despite ploughing a lone furrow up front on his own for an hour, Rooney trudged unhappily off the field and then threw his boots down in disgust as he made way for the joint arrival of Michael Owen and Dimitar Berbatov.
"It was always part of our thoughts to bring Wayne off,'' confirmed Ferguson. "He had been playing as the lone striker for an hour, which is why he was always going to come off. He is never pleased to come off. He has so much energy he wants to play all the time.''
Having predicted his team would provide United with a stern test, Besiktas coach Mustafa Denizli was disappointed to miss out after coming so close to snatching a point. "I am sad about the result,'' he said. "To concede so late after putting in so much effort is quite demoralising.''