NINE points clear and counting at the top of the table but without quite looking the part, Manchester United were just happy to get yesterday's derby of the way and leave Chelsea to worry about their's this afternoon.

After Wayne Rooney's early goal, Louis Saha bundled in a second but instead of settling them, that seemed to induce a mood of complacency. Alex Ferguson even sent on John O'Shea to shore things up, only for City to score within four minutes and bring about the odd moment of anxiety before Cristiano Ronaldo benefited late on from one of the visitors' many defensive errors. To compound City's misery on a ground they have not left victorious for 32 years, Bernardo Corradi's blatant dive in added time brought him a second yellow card.

Overall, however, this was a day for damping down expectation rather than encouraging it. It was by no means one of United's more fluent performances, for all the excellence of their three leading performers this season, Ronaldo, Paul Scholes and Ryan Giggs. Ben Thatcher, the unfortunate assigned to controlling the Portuguese winger this week, handicapped himself and his team by collecting a booking after only 13 minutes and could not risk any of his wilder challengers thereafter.

He received little support from Darius Vassell, the attacking midfielder in front of him, and could not cope on his own, especially as Richard Dunne and Sylvain Distin had one of their more erratic afternoons.

City's most promising moments tended to come either from set pieces or knocking crosses into the penalty area and winning the second ball, often headed away without as much conviction as Ferguson would have wanted. But the manager was prepared to make allowances for his team in their fourth important win in 11 days. "It was a typical derby game, " he said. "We had some fantastic opportunities but at other times really had to scrap. The legs were going a bit. It's a bit unfair, the television organisation, I think it's wrong that a team playing on Wednesday night has to play on Saturday lunchtime."

Not that there was much wrong with their start, even as City made intentions clear with fouls by Joey Barton on Ronaldo after 10 seconds and Corradi on Michael Carrick after 90. Barely five minutes had elapsed when Ronaldo chested the ball down and was allowed without hindrance to place a low cross right into the path of Rooney for an easy finish. Oddly, he has scored in only four games this season.

One of City's problems is that they have scored in only four of their last ten. Stuart Pearce stuck with two strikers when he might have been expected to reinforce the midfield, though it was his young right-back Micah Richards who twice might have forced an equaliser. In the 21st minute he knocked Thatcher's long, diagonal free-kick wide after Gabriel Heinze and Rio Ferdinand failed to clear, and 20 minutes later his prodigious leap to meet Barton's corner brought a downward header that Georgios Samaras could not turn in.

Richards had barely returned to his defensive position before Hatem Trabelsi's error out on United's left allowed Heinze to cross low for Louis Saha, reacting much more sharply than two defenders, to score his fourth goal in five games. "We gave cheap goals away, which is costly when you play the big boys, " Pearce admitted.

"We've ended up shooting ourselves in the foot."

Nicky Weaver was injured attempting to stop Saha, so Andreas Isaksson was required not only to come on in goal for the second half, but to make good saves from Rooney, twice, and Giggs when United roused themselves sufficiently. Stephen Ireland was also a useful substitute, for the ineffectual Claudio Reyna, though his shot three minutes into the half was one of too few to trouble Edwin van der Sar.

Ireland it was who set up Trabelsi for the one that beat the Dutchman, well struck off the bar from 20 yards.

But alarms after that were minor, and rendered irrelevant six minutes from the end when Dunne completely failed to cut out Rooney's low centre and Ronaldo, just onside, enabled Old Trafford to go into "Let's all laugh at City" mode. The jeers were redoubled when Corradi fell over in the penalty area and was sent off, earning a commendable rebuke from his own manager. "Hopefully after I've had a word this week, he'll stay on his feet a bit better, " Pearce threatened.

As for United, the requirement is to keep feet firmly on the ground.