Third Division Swansea pulled off the shock of the FA Cup this season with a famous victory over Premiership high-fliers West Ham at the Vetch Field.

Hundreds of jubilant home fans invaded the pitch at the final whistle to embrace their heroes after they booked a fourth round clash with Derby.

Martin Thomas' 29th-minute goal was enough for John Hollins' side to send the Hammers crashing to another embarrassing cup exit after being knocked out of the Worthington Cup by lowly Northampton.

It was the first time a Third Division side had beaten top flight opposition since the start of the Premier League in 1992 and was belated reward for their superb performance in the first meeting which ended 1-1.

At Upton Park they were denied by a Julian Dicks equaliser with three minutes left but there was to be no great escape for West Ham this time.

And goalkeeper Roger Freestone more than made amends for his blunder 11 days ago when he allowed Dicks' shot to squeeze under his body, pulling off a breathtaking save from Neil Ruddock's goalbound effort three minutes from time.

The visitors threw everyone forward at the death and pinned Swansea back in their own half, but a valiant rearguard action, with first-game hero Jason Smith and Matthew Bound outstanding, kept West Ham at bay.

Thomas, a free transfer from Fulham in the summer, was already a hero at the Vetch after scoring in the win over fierce rivals Cardiff in November, and he will probably be granted the freedom of the city after his right-foot shot past Shaka Hislop set up victory.

West Ham started much better than in the first meeting between the sides and enjoyed the best of the opening exchanges of the replay.

John Hartson, returning to his home town, played a neat one-two with Trevor Sinclair on the edge of the area to create some space but instead of shooting tried to flick it back again to Sinclair and Jason Smith hacked the ball clear.

Sinclair then just failed to make contact with an audacious overhead kick before Hartson shot straight at Freestone, all in the space of the first 10 minutes.

The Hammers were clearly benefiting from the return of Frank Lampard in midfield who missed the first match at Upton Park.

From Lampard's 11th-minute corner Ruddock sent a glancing header wide after a good late run into the area and just two minutes later Lampard forced Freestone into a brilliant save.

The midfielder's right-foot shot looked destined for the top corner before Freestone threw himself to his right to turn the ball round for a corner.

Dicks was then booked after a tussle with Stuart Roberts as the niggly fouls which almost marred the first game threatened to resurface.

From the resulting free-kick the home side almost opened the scoring after 21 minutes, Martin Thomas curling a right-foot shot against the top of the bar with Hislop beaten.

The home fans didn't have long to wait for the first goal however as Thomas put Swansea in front just before the half hour.

The influential midfielder picked up the ball from Jonathan Coates some 25 yards out and gave Hislop no chance with a right-foot effort that dipped and curled into the bottom corner.

That sent the Swansea fans wild with several spilling onto the pitch and it was a few minutes before order was restored.

West Ham boss Harry Redknapp made a change at half time bringing on Eyal Berkovic for Emmanuel Omoyinmi. And the Israeli international gave a fresh impetus to the Hammers attack as they desperately sought an equaliser.

His ball released Sinclair down the right flank but Freestone was quick to cut out the danger from Sinclair's ball back across the face of goal.

Berkovic then dragged a shot wide before the visitors should have equalised on 63 minutes.

His delightful back heel sent Stan Lazaridis racing to the byline but when he pulled the ball back there was no-one following up to steer the ball into the empty net.

Swansea continued to look dangerous on the break however, Roberts breaking clear only to be denied by Lampard chasing back 40 yards and dispossessing the Swans winger on the edge of the area.

West Ham threw everyone forward with Ferdinand pushed into midfield but they still could not beat the home defence.

Hartson glanced a header just wide from Lampard's corner but just seconds later Thomas' goalbound effort from just 10 yards was diverted inches wide, and the Welshmen survived to record a famous Cup victory.

Teams

Swansea: Freestone, S. Jones, Howard, Cusack, Smith, Bound, Coates, Thomas, Alsop, Watkin, Roberts.

Subs Not Used: Price, J. Jones, Newhouse, Lacey, Casey.

Booked: Howard, Cusack, Bound, Freestone.

Goals: Thomas 29.

West Ham: Hislop, Ruddock, Ferdinand, Dicks, Breacker (Hall 72), Lampard, Lomas, Lazaridis, Omoyimni (Berkovic 45), Hartson, Sinclair.

Subs Not Used: Forrest, Abou, Potts.

Booked: Omoyimni, Dicks, Breacker, Sinclair.

Att: 10,116

Ref: S Lodge (Barnsley).