DEJECTED Sunderland supporters trooped away from the Stadium of Light wondering if the bubble has burst.

Normally they leave the ground excited and full of praise for a hard-fighting display, or up in arms about another controversial performance by the referee. But this time there was a grudging acceptance of a deserved FA Cup fifth round home defeat by a slicker and superior West Ham.

It was the Wearsiders' fourth game without a win, and even allowing for disruption through injury and suspension, the well below par performance did not inspire confidence for the hard fight ahead to secure a place in Europe.

The feeling of uncertainty and lack of belief on the pitch seemed to transmit itself to the watching faithful, sadly upstaged by the 5,000 West Ham early birds who had risen before the larks to depart London at 4.30am.

Sunderland went into what was always bound to be a difficult match against the FA Cup conquerors of Manchester United without four regulars and it was soon pretty obvious that the patched-up side was only a pale shadow of the team which has battled its way to fourth place in the Premiership.

When Slovakian international Stanislav Varga limped off with a groin strain in the 22nd minute, forcing a reshuffle of the home defence, the odds against progress into the quarter- finals lengthened considerably.

West Ham, inspired by the exciting young talents of Joe Cole, Michael Carrick and Frank Lampard, took a firm grip on the game and, after squandering a handful of first half chances, produced a deserved match-winner from French striker Frederic Kanoute.

Sunderland, in contrast, huffed and puffed, gambling on risky offside tactics, and mustered only one worthwhile shot at goal.

Peter Reid made no attempt to seek excuses for his team's disappointing performance. He simply admitted that West Ham were the better side.

The Sunderland boss held up his hands and said: "Sometimes you have to give credit to the opposition and that's what I'm going to do.

"They defended deep and made it very difficult for us. They were certainly very dangerous on the break and it was that type of game.

"Possibly if we'd got one it might have made it a more open game, but all in all you have got to give credit to West Ham and say it was a game they deserved to win."

On their previous visit to Wearside in September a weakened West Ham side had to dig deep to earn a point. This time they carried the game to Sunderland with an assurance and enterprising ability which could take them all the way in the competition.

The gangling Kanoute promised to be the villain of the piece for the Hammers after some atrocious ball control in front of goal in the first half, when he spurned three glorious chances.

The home fans must have been glad it wasn't the much more accomplished Paulo Di Canio who went charging through on goal in the fifth minute.

Kanoute tumbled the ball towards goalkeeper Thomas Sorensen, then five minutes later he used his speed to squeeze between two Sunderland defenders. But his finish from ten yards was inaccurate, then he was denied a chance by Stefan Schwarz after leaving Varga in his wake.

Reid gambled on crowd favourite Julio Arca and Welsh international John Oster supplying some decent ammunition from the wings for Niall Quinn and Kevin Phillips, but it did not materialise, with the little Argentinian only coming to life after the break.

Oster's main contribution was a promising run through the middle in the 31st minute, when he cleverly beat his man well on the edge of the box but did not get proper contact with a left-foot shot.

Quinn and Phillips had largely to forage for themselves, receiving little time or space from the efficient central defensive combination of Igor Stimac and Christian Dailly, who restricted Phillips to one first half shot, which was deflected to safety.

In midfield, Sunderland missed the ingenuity of the suspended Don Hutchison and could not match West Ham's bite and brighter, more ambitious use of the ball against a suspect offside trap.

Sunderland were finally caught out in the 76th minute after a great build- up by Lampard, who had a vicious right-foot shot parried by Sorensen just before half-time.

This time the Danish keeper was at fault as he spotted Lampard snaking through the middle, but was undecided about the right position to adopt and his hesitation allowed Kanoute to accept a well-measured pass to fire home a right-foot shot from the edge of the penalty area.

Sorensen has been Sunderland's saviour time after time this season, but his one mistake proved crucial.

Reid said: "I have got to say my keeper has had a fantastic season and I wouldn't swap him for anybody. But I just thought he made a wrong decision that probably cost us.

"But it was going to be something like that. It was going to be a mistake or a piece of magic and Tommy made the mistake. It is unfortunate for goalkeepers because when they make mistakes they are punished."

West Ham could have tied it up immediately afterwards when Di Canio freed Kanoute with a great pass, only for the Frenchman to fire across the face of goal.

The home defence came under tremendous pressure at this time and Brazilian Emerson Thome, back after injury, deserved credit for his stalwart performance in a back four disrupted by the Varga injury and rejigged to accommodate 19-year-old left back George McCartney, who could have wished for a less arduous call-up.

Sunderland tried to force a grandstand finish, but they found evergreen defender Stuart Pearce in an uncompromising mood when it mattered most, making one crucial block on Oster as the winger tried to snatch an equaliser after a brilliant through-ball from Phillips.

Reid made no attempt to look for excuses, saying: "Injuries and suspensions are part and parcel of football.

"I put out what I considered was our best side and it wasn't good enough on the day. That happens in football.

"We are in the middle of a bad spell of results but our performances have not been that bad and we have enough quality to get out of it and we will do."