Burnley became only the second home team this season to inflict defeat on high flying Watford in the Championship.
In an enthralling encounter at Turf Moor, with both sides intent on attacking each other from the off, the Clarets put on a fine performance going forward to rack up four goals and give the Hornets defence an afternoon to forget.
The match also saw first goals for the club for Jon Harley and Graham Branch's first goal of the season before James O'Connor wrapped things up to seal the points, after Marlon King's strike had temporarily brought Watford back into it in the second half.
Burnley were also boosted to see the return of defender Wayne Thomas, who was introduced in the dying moments after his recovery from a knee injury.
There wasn't too much to note in the first half hour of the game though, despite Hornets striker King proving to be a handful in his lone striking role. He was the first player to find a shot on target, although Brian Jensen easily saved his low strike from the edge of the box.
Watford's veteran defender Malky Mackay's lapse in concentration then allowed Ade Akinbiyi a run at goal, but he lost his footing at the crucial moment and with no support in the box, the chance was gone.
Jensen had to make another routine save in the 25th minute, when Gavin Mahon drilled a strike at goal from the outside of the area after an earlier Watford corner was headed clear.
Matthew Spring then had a good chance when he nicked the ball off Micah Hyde, but after dribbling into the box, his shot was weak and Jensen made a simple stop.
Burnley had the breakthrough after 32 minutes though when Clarke Carlisle, not for the first time in the game, took a heavy first touch just inside his half. Branch was in quickly to whip the ball off him and around him to break away down the left. He had too much pace for both Carlisle and Mackay as he brought the ball into the box. With Akinbiyi lurking at the far post, Branch chose to shoot himself and made no mistake by smashing an angled low shot past Foster and into the bottom corner of the net.
Less than 10 minutes later and with just five minutes of the first half remaining, Burnley had a second goal thanks to a poor decision by Foster in the Watford goal, who stepped out of his area when kicking the ball out of his hands. The referee's assistant spotted that and Burnley were awarded a free kick on the edge of the box. With John Spicer and Nathan Dyer stood over the ball, Harley suddenly stepped forward to strike a low shot through the wall and into the bottom corner of the net to find his first goal for the Clarets.
Watford responded at the break by making two substitutions and throwing Carlisle up front to join King and add some physical presence to the Hornets' attack. They started the second half well too and Spring's header from Paul Devlin's right wing cross forced Jensen into a brave save low to his right.
King then saw his shot well blocked by John McGreal, after turning neatly in the box when collecting substitute Anthony McNamee's ball in from the left.
At the other end, Spicer and Hyde combined well in midfield to pick out Michael Duff on the right and Foster had to be alert to save his vicious cross-shot from a tight angle.
Hyde then tried his luck with a shot after a weaving run across the pitch from Dyer, but Foster saw it coming and made a good save.
Watford got themselves back in it just after the hour mark though, when Burnley gave King too much space on the edge of the box. He needed no second invitation and picked out the bottom corner following a swift turn and shot.
Watford were enjoying their best spell of the game by now and Burnley had Jensen to thank for keeping them ahead in the 66th minute when he made a smart double save to deny Spring first and then Carlisle, who looked to pick up the rebound.
Burnley weren't without their chances though and Mackay made a crucial header to cut out Branch's left wing cross with Akinbiyi unmarked at the far post. From the resulting corner, Harley's cross picked out substitute Gifton Noel Williams at the far post and his header looked to have extended the lead only for Devlin to clear off the line.
Noel Williams had made a big difference since his introduction by holding the ball up well and with 77 minutes gone, Burnley extended their lead after winning a penalty. Hornets defender Lloyd Doyley played a back-pass into the area which Branch latched onto and knocked past Foster, who proceeded to trip the Clarets winger in the box. Harley stepped up and sent Foster the wrong way to make it 3-1.
Just two minutes later, the points were secure when Noel Williams flicked a ball on through the middle. James O'Connor raced clear from midfield into the area and finished well past Foster, whose afternoon was going from bad to worse.
He made partial amends though, when he made a good save to deny Akinbiyi after he shot left footed from inside the box. That proved to be the last of the chances with Burnley finishing the game the stronger and looking to add to their tally.
Burnley: Jensen, McGreal, Sinclair, Duff, James O'Connor, Hyde, Branch (Thomas, 87) Akinbiyi, Spicer (Noel Williams, 67) Harley, Dyer (Elliott, 90) Subs not used: Grant, Garreth O'Connor.
Watford: Foster, Mackay, Stewart, Doyley, Carlisle, Chambers (McNamee, 45) Mahon, Spring, Diagouraga (DeMerit, 45) Devlin (Grant, 73) King. Subs: Chamberlain, Francis.
Bookings: Ade Akinbiyi (39 minutes), Ben Foster (40 minutes), Nathan Dyer (45 minutes).
Sending offs:
