IF Bryan Robson ultimately fails to drag himself out of the mire at Middlesbrough, he will surely reflect on one defining moment in this game at Old Trafford.

Lightning was threatening to strike twice after Christian Karembeu - of all people - handed Boro an improbable lead which offered realistic hope of another memorable triumph at the Theatre of Dreams.

But as the hour-mark was approaching, with Boro still a goal to the good, a golden chance to double the advantage was lost and before long Robson's men were heading for their sixth successive defeat.

Middlesbrough-born Andy Campbell was suddenly presented with the most inviting of openings, yet somehow failed to hit the target.

Deep inside the home penalty area and in front of goal, the England Under-21 striker tried to wrap his right-foot around the ball but couldn't do so and screwed his shot wide.

In the context of the game, Boro boss Robson almost gave off an air of resignation with a wry smile and a quiet curse through pursed lips as he saw his side's chance to repeat their 3-2 victory here two seasons ago, begin to slip away.

Sure enough, six minutes later United were level, their dynamic skipper Roy Keane delivering a low cross for Nicky Butt to tap in his second goal of the season from close range.

Butt had atoned for surrendering possession to Karembeu in the build-up to the Frenchman's first Boro goal.

The dreadlocked midfielder has been a massive disappointment since his £2.1m summer arrival from Real Madrid and Robson had dropped him for the previous week's 1-0 home defeat by Arsenal.

Karembeu had a point to prove and made it in the 31st minute when, having left Butt in his wake, he cleverly exchanged passes with Hamilton Ricard before lobbing the ball over fellow countryman Fabien Barthez in the United goal.

Minutes later, Boro's travelling fans were chanting "there's only one Bryan Robson'', a little ditty rarely heard these days.

The same song emanated from the other end of the ground soon after Teddy Sheringham, a 40th-minute replacement for the injured Ole Gunnar Solskjaer, had fired home his 13th goal of the season to effectively seal Boro's fate in the 65th minute.

It was a measure of how much former United captain Robson is still revered, rather than any attempt at mockery, that the Stretford Enders sang his praises.

A rueful Robson, facing up to another defeat, managed to respond with an affectionate wave.

There are those among the Boro faithful who would like to see Robson wave goodbye to the Riverside and if further defeats follow over the next two games at home to Leicester and Bradford, it is difficult to see how he can cling on to his job, irrespective of the support he enjoys from chairman Steve Gibson.

Boro are in danger of becoming entrenched in the Premiership's bottom three and they badly need to glean at least four points from the next six on offer.

To do that, they must show the same determination and battling qualities which have characterised their last two performances.

And the onus is on the likes of Karembeu, reputedly being paid £40,000-a-week, to perform the way he did on Saturday.

Robson believes the return from injury of Paul Ince, Ugo Ehiogu and Alen Boksic will act as a stimulus to Karembeu, who earned the plaudits at Old Trafford.

"I thought he was excellent and so was Gary Pallister at the back,'' said Robson.

"I couldn't have asked for any more from those two.

"Christian has been used to playing in dominant teams with very good, international players around him. I think he performs well on the big stage.

"With Ince, Ehiogu and Boksic coming back into the frame, I think that will bring the best out of Christian.''

Boro keeper Mark Schwarzer, out for eight weeks with a broken thumb, has been another key casualty.

The giant Aussie, whose mistake gave David Beckham the opportunity to score the only goal between the sides here last season, couldn't have had a more testing return.

He produced crucial saves but was powerless to prevent the tide turning against Boro.

"That's what happens when you come to Man United,'' said Schwarzer.

"They can play well without scoring - then step up a few gears and score at will.

"I was more nervous before the game than normal because of the games I've missed, but I was still happy with my performance.

"I thought if we could hold them a bit longer in the second half, we might get away with a point, but it's never over with Man. United.

"We showed a lack of discipline in certain areas, but we've played well against Arsenal and Man. United.

"We only had ten men against Arsenal but we gave a good account of ourselves and we've done well again.

"We've only been beaten by a goal both times and with a bit of luck we could have got something.''

All but one of Boro's six straight defeats have been by a single-goal margin and their luck has certainly been out with injuries.

But now it's time they made their own luck by playing to their potential in every game - whatever the opposition