Watford's dream of an immediate return to the Premiership was shattered at the KC Stadium this evening as Hull set up a winner-takes-all showdown with Bristol City at Wembley a week on Saturday with a resounding 4-1 victory.

Trailing by two goals after the first leg, Watford halved the arrears through Darius Henderson after just 12 minutes of a rousing match and looked capable of staging the most unlikeliest of comebacks during a first-half that witnessed arguably their best footballing performance of the season.

But Hull dashed their hopes with a crucial goal just before half-time from Nick Barmby and then rubber-stamped their place in the final when substitute Caleb Folan powered in a header on the hour mark. Richard Garcia added the coup de grace with a superb individual goal late on while Nathan Doyle's simply rubbed salt into Watford's gaping wounds by scoring a deflected fourth.

While Hull, who won the tie 6-1 on aggregate, are now dreaming of playing top-flight football for the first time in their history, Watford are left wondering how they blew an eight-point lead at the top of the table and contemplating another season in the Championship.

The game exploded into life after just 90 seconds when Nathan Ellington, who enjoyed an excellent first half before fading badly, caught Wayne Brown with a high foot. The Hull players were incensed by the challenge but referee Mark Clattenburg diffused the situation excellently and just let the Watford striker off with a warning.

John Eustace enjoyed Watford's first attempt at goal following some neat interplay, but it was heart in your mouth time at the other end when Adrian Mariappa's header back to Lee was telegraphed by Fraizer Campbell who was quickly smothered by the alert Watford keeper.

But that was the only blemish on a hugely impressive start from the Hornets who stroked the ball around with real panache and confidence. And their neat interplay reaped dividends after just 12 minutes when a patient, incisive move involving the excellent Mat Sadler, Jobi McAnuff and Lee Williamson resulted in Henderson tucking the ball home from close range. It was Henderson's 13th of the season and what a time to get it.

The confidence surged through the veins of the players thereafter and they controlled the first half, causing a nervous home side problems down both flanks and through the middle where Nathan Ellington, playing in a slightly withdrawn role, was causing havoc.

It took Hull until the 21st minute to win their first corner and the only time they really tested Lee was when Dean Windass fired a speculative volley over the bar from long range. Sensing their first ever appearance at Wembley, the home crowd were becoming increasingly edgy and Phil Brown would have been the manager praying for half-time as a first-half Watford controlled drew to a close.

However just when Boothroyd was about the contemplate delivering his half-time team-talk and commend his players on half a job well done, disaster struck. A cross was headed into the air by Jay DeMerit, Lee came to collected only to hesitate and find himself in no-man's land. Dean Windass headed the dropping ball over the stranded Watford keeper and Barmby raced in to nod the ball over the line. It was just the tonic the home side needed and left Watford punch drunk.

Watford suffered a lucky escape just after the restart when Lee Williamson appeared to intercept some neat close control from Windass with his hand, but even the most ardent Hull fan would not have begrudged the Hornets a slice of good fortune following events in the first leg at Vicarage Road.

Needing two unanswered goals to take the match into extra time Boothroyd went for broke on 58 minutes, introducing Tamas Priskin for Mariappa in bold attacking move. The move almost paid off immediately, the Hungarian forcing a fine save from Bo Myhill with a rasping shot following some neat link-up play with Smith. The winger then forced Wayne Brown, the former Hornet, to nervously slice the ball across his own goalmouth with a teasing centre.

Hull boss Phil Brown could have switched to a more defensive formation to counter Watford's renewed attacking threat but, to his credit, he stuck to his guns and replaced Windass, who received a standing ovation, with Caleb Folan in a like for like swap.

And it was Folan who put the tie beyond the reach of the plucky visitors, planting a firm header past Lee from a Garcia cross to send the home crowd delirious. Folan almost helped put the icing on the cake by crossing for fellow Craig Fagan to head over the bar, while Fagan whistled a sizzling effort just over the bar seconds later.

In a rare second-half attack from the visitors, Henderson saw a header from a McAnuff corner cleared off the line by Bryan Hughes and could not muster enough power to force home the rebound.

The remainder of the match turned into a celebration for the home supporters, with a Mexican wave sweeping round the ground and cries of 'We are going up' reverberating around a jumping KC Stadium that erupted when Garcia waltzed through the heart of the Watford defence to score a stunning third on 88 minutes. The home fans were in dream land 60 seconds later when Doyle beat Lee with a deflected fourth on the break.

It was all too much for the dejected visiting fans who were left contemplating a long journey home and wondering just where it all went so badly wrong.

To rate the performances of the players against Hull, click here

Hull: Myhill; Ricketts, Brown, Turner, Dawson; Garcia, Ashbee, Hughes, Barmby (Fagan 72); Campbell (Doyle 78), Windass (Folan 64).

Subs not used: Duke, Walton.

Watford: Lee; Mariappa (Priskin 58), DeMerit, Bromby, Sadler; Smith, Eustace, Williamson, McAnuff; Henderson, Ellington (Ainsworth 78).

Subs not used: Poom, Doyley, O'Toole.

Bookings: Barmby (23), Turner (67).

Att: 23,155