Not even one mad moment can stop United's dazzlers teaching shambolic City a football lesson

Gary Neville may have let himself down when he lost control for the first time in his honour-laden career against Manchester City on Saturday.

But when the England right-back was sent off for head-butting Steve McManaman five minutes before half-time, he did those of us lucky enough to be inside Old Trafford a great favour.

Call his gift to this Valentine's Day clash a bouquet of barbed wire if you want, but Neville's dismissal in the Manchester derby turned a cold, clinical match into a passion play of rare intensity.

In the 50 minutes that remained, it became a classic, an encounter inspired by the swashbuckling resistance of 10 men in red who played as if the romance of the cup flowed through their veins.

Asked to rise to the challenge of keeping City at bay, United did far more than that. A goal ahead through a first-half prod from Paul Scholes, their backs were to the wall but, instead of just standing firm, they put their heads down and charged.

In the process, they may even have restored their sliding self-belief. Last season, humiliating defeat at Maine Road spurred them on to an unstoppable title dash.

Now, victory over City against the odds may have given them the boost they need to redouble their attempts to overhaul Arsenal once more.

Because this was a United display built on a series of heroic performances in every department of the team.

Roy Keane, playing with the gentle limp that is the legacy of his hip operation, was almost super- human in his determination not to yield.

Forget 'inspirational'. That didn't do him justice on Saturday. He was utterly dominant in midfield, snapping at heels, never giving City time to settle.

Instead of tiring as the game went on, this titan of a player who is supposed to be slowing down grew stronger and stronger.

In the 80th minute, it was Keane surging to the back post and heading Ryan Giggs' free kick back across the six yard box.

Ruud van Nistelrooy was lurking there, of course, ready to tap the ball into the empty net for United's clinching fourth goal.

Three minutes later, Daniel van Buyten, City's new on-loan centre-back, dwelled on the ball a split- second too long near the half-way line as he prepared to launch another long ball forward.

He probably thought the match was over, that United would be sitting back by now. It was at that point that he was hit from the side by the juggernaut of a perfectly-timed Keane tackle.

Keane was the leader but he had generals everywhere. Van Nistelrooy was superb in attack, more ruthless than ever in front of goal, working ceaselessly and alone up front.

He labours with the nobility of a pit-pony, shoulders hunched with effort and will, always striving and always delivering.

It was the Dutchman who had latched on to Cristiano Ronaldo's searching cross to ram United's second home at the back post when City were pressing for an equaliser.

And then there was Phil Neville, so often in Gary's shadow but now playing for both brothers.

In the first half, he was brutal in the simplicity he brought to United's midfield. In the second half, he filled in flawlessly at right-back.

He won every tackle he made, he broke up play without fuss and never misplaced a pass, even the ambitious ones he spread wide out to Ryan Giggs on the left.

And second only to Keane, there was Tim Howard. The subject of subtly mounting criticism recently, he put a full stop to that trend with this display.

One reaction save from City's outstanding performer, Joey Barton, just before an hour had passed, almost beggared belief and seemed to sap City's rising hopes of a rally.

But there were others, notably a block to a weak McManaman volley and a parry of a drive from Shaun Wright-Phillips.

There was nothing Howard could do to stop Michael Tarnat's bullet 12 minutes from the end that gave City a flicker of hope.

And even if he was at fault when Robbie Fowler drifted a quick 86th-minute free-kick into the corner of the net while Howard was still organising his wall, the match was won by then.

For a parsimonious few, the match merely added to concerns about United's porous defence because of the frequency of the chances City made.

But that is to ignore the inconvenience of them being a man down for more than half the game.

It is not in their make-up to play tight and cagey because they are football adventurers.

And it was their adventure that won the day at Old Trafford.

They made it feel as if they were the unstoppable force even though they were at a numerical disadvantage.

City discovered what it is like when that kind of inspiration grips you when their 10 men came back from three-nil down at Spurs in the fourth round.

On Saturday, though, they had to bow to a team that cut them to pieces with 10 men instead.

United will take heart as they prepare for greater tests.

For City and Keegan, it is starting to feel like the end of the affair.