Watford striker Matěj Vydra scored a brilliant winning goal as Brentford were beaten at Vicarage Road.
The home side took the points with a 2-1 win but Brentford were worth a share of the spoils.
They fell behind late in the first half but Jonathan Douglas equalised after the break and The Bees looked as if they had the upper hand.
But Vydra smashed in a superb winner from around 25 yards inside the final 20 minutes.
The home side dominated the first quarter of the match, flooding men forward and creating good chances.
The Bees were stretched at the back and forced to defend desperately at times but they got to the midway point of the first half with the game at 0-0.
However, it took the intervention of the woodwork and some good defending to make it so.
Douglas made a good early tackle to prevent Diego Fabbrini playing a one-two with Vydra and getting a shot away.
And the midfield player made another important interception soon after when Vydra got away on the right and delivered a cross that was set for Fabbrini at the near post.
Vydra was the main threat, finding pockets of space and using his attacking wide players, particularly Lloyd Dyer on the left to hurt The Bees.
He looked like the man most likely to make something happen for the hosts.
Vydra had a shot deflected wide after wriggling free before striker Odion Ighalo also went close from a corner, seeing his effort diverted wide.
Dyer set up Ighalo soon after for another shot that the Brentford defence snuffed out and the striker headed against the crossbar soon after.
Alan McCormack made a fine recovery tackle when Dyer looked to have taken advantage of a ricochet.
And Tony Craig was in the right place to make a similarly important tackle when Ighalo looked set to turn home a Dyer cross before Vydra shot wildly over at the far post from a corner.
It was a fantastic start from the hosts, full of attacking intent and inventive forward play but Brentford weathered it and by the half hour they were well in the game.
They started to create chances of their own – Toumani Diagouraga shot wide after a quick break and Andre Gray saw an effort blocked after a good turn.
Watford goalkeeper Heurelho Gomes was forced in to a low save when Douglas met an Alan Judge free kick on the volley and a better one soon after when Jota, after a sublime piece of skill, let fly from 18 yards.
Judge then went close with a 25-yard volley but just when it looked like Brentford would take the initiative in to half time, Watford struck.
It came from a penalty, awarded by referee Graham Salisbury, after a long think, for a foul by James Tarkowski on Ighalo.
The home side had broken free and the ball was moved by Daniel Tőszér to Vydra, he released Ighalo and Mr Salisbury decided Tarkowski had committed a foul when the pair came in to contact with each other.
Ighalo took the penalty but his low effort was saved by Button, however the striker reacted quickest and followed up to score.
Brentford came straight back at the home side and could have levelled before the break.
Moses Odubajo delivered from the right, Jake Bidwell knocked it back, Douglas had an effort blocked and Gray was crowded out as he tried to finish.
Watford probably deserved to be ahead on the balance of play in the first half but the goal arguably came against the run of play at the end of the opening 45.
Brentford came out after half time looking to get back on terms and went at their hosts.
After a move started by a superb Diagouraga tackle, Gray was just unable to turn in a Bidwell cross and Jota volleyed an Odubajo cross wide soon after.
Button had to rush out to save at the feet of Dyer and Gianni Munari had a shot blocked but Brentford had the momentum and just before the hour mark they had an equaliser.
The goal was one to savour for Douglas, who finished off a sweeping move.
Brentford had been on the attack when Bidwell played a ball forward, Odubajo darted in to Watford territory and fed Judge, his pass was inch perfect for Douglas, who slotted past Gomes.
The Bees had the bit between their teeth and went looking for the lead – Gray was just unable to turn in an Odubajo cross and then headed a delivery from Judge wide.
Craig had to make an important clearance from a Daniel Pudil cross that Ighalo was waiting to put in but Brentford had the initiative only to concede again with 20 minutes to go.
It came out of nothing – Brentford were penned back for a short period but clearing their lines when Vydra smashed an unstoppable shot home from 25 yards.
It was almost three soon after when Button saved at the feet of Vydra, who miss controlled an Ikechi Anya cross after the substitute had picked up a poor clearance.
Tőszér then went for goal from the halfway line but missed the target.
The home side were content to sit deep, allow Brentford to play in front of them and invite The Bees to break them down.
The Bees struggled to create many openings and had to be wary at the other end – a Tőszér shot was blocked and an Anya effort deflected wide of the far post.
One they did create fell to Odubajo, who cut in off the right but curled a left footed effort over the bar.
Brentford piled on the pressure late on, Gomes held on to a Nick Proschwitz header before making a superb save low to his right from a Douglas header.
The hosts could have added a third late on – Button saved from Anya and Dyer saw a shot blocked – but were reduced to ten men in the dying seconds when left back Danny Pudil was sent off for a second bookable offence.
Watford still almost got one at the death on the break when Anya raced away but Button denied Dyer.
It was not, however, enough to prevent Watford getting the win.
Watford: Gomes; Parades, Ekstrand, Cathcart, Pudil; Tőszér, Munari; Fabbrini (sub Anya 58 mins), Vydra (sub Hoban 90 mins), Dyer; Ighalo (sub Abdi 73 mins)
Subs (not used): Bond, McGugan, Murray, Mensah
Bookings: Ighalo (43 mins), Fabbrini (51 mins), Paredes (90 mins)
Sent Off: Pudil (90 mins) (second bookable offence)
Brentford: Button; McCormack, Tarkowski, Craig, Bidwell; Douglas, Diagouraga (sub Proschwitz 79 mins); Odubajo, Judge, Jota (sub Pritchard 69 mins); Gray
Subs (not used): Bonham, Tébar, Toral, Dean, Betinho
Bookings: Tarkowski (43 mins) (fourth of season), McCormack (90 mins) (second of season)
Attendance: 15,502 (1,931 away fans)
By Chris Wickham