Few people suspected that every one of Manchester City’s supporters would stand in silent tribute to the victims of the Munich air disaster before their derby match at Old Trafford yesterday and fewer still imagined that they would be celebrating afterwards, with a 2-1 victory inflicting a serious blow to Manchester United’s Barclays Premier League title challenge.

Goals from Darius Vassell and Benjani Mwaruwari, on his debut for the club, earned City their first win at Old Trafford since April 1974 and meant that Sven-Göran Eriksson, the City manager, had achieved back-to-back victories over United in his first two attempts. It is a result that few predicted on an afternoon when United marked the 50th anniversary of the Munich tragedy, but it was one that could have a serious impact on the title race, leaving Sir Alex Ferguson’s team two points behind Arsenal, who will move five points clear at the top if they beat Blackburn Rovers at the Emirates Stadium this evening.

It will be remembered as the day the two Manchester clubs came together to pay an emotional tribute to the 23 victims of the Munich disaster, in which eight United players were killed, on February 6, 1958. Contrary to many fears, City supporters joined their United counterparts in observing a minute’s silence impeccably, earning applause from Ferguson for doing so. The only interruption came from outside the ground, where six fireworks were let off. Greater Manchester Police closed an investigation into that incident last night without making any arrests.

“I am extremely proud of our team,” Eriksson said. “But everyone who belongs to City must be proud of what our fans did here. Their behaviour was fantastic. There was a little concern that something may go wrong, but they were not just good, they were perfect.”

Both clubs wore specially commissioned kits for the match — with United’s players wearing a 1950s-style strip, numbered from 1 to 11 with no sponsor’s logo — but it was City who rose to the occasion, with Vassell and Benjani giving them a 2-0 lead at half-time. Michael Carrick, the United midfield player, scored in the final seconds, but that was scant consolation.

“It was nice to see the minute’s silence went down really well,” Carrick said. “But in terms of the game, we’re not going home happy. It’s hard to say what went wrong.”

Carlos Queiroz, the United assistant manager, declined to use the emotional atmosphere as an excuse for a poor performance, citing fatigue from last week’s international fixtures. “We didn’t look our usual selves,” he said. “Seven or eight of our players played 90 minutes for their countries on Wednesday. Sometimes that affects you and today was one of those days.”

Chelsea are in contention, but a goalless draw at home to Liverpool leaves them five points adrift of Arsenal. “We can still win the title,” Avram Grant, the first-team coach, said. “It will not be easy, but we can do it.”