Match ends, Watford 2, Brentford 1.
A superb strike from Matej Vydra gave Billy McKinlay a victory over Brentford in his first game as Watford boss.
McKinlay was only named Hornets head coach on Monday, following Oscar Garcia's decision to step down for health reasons.
Odion Ighalo followed up his own saved penalty to put Watford in front, but the Bees' Jonathan Douglas equalised.
Vydra's half-volley won the game for Watford, who finished with 10 men after Daniel Pudil's late sending off.
Brentford went close to snatching a late equaliser but Heurelho Gomes did well to keep out Alan Judge's header.
Watford join Championship leaders Norwich and second-placed Nottingham Forest on 20 points.
McKinlay is Watford's third manager in the past month, after Garcia's decision to step down following a week in hospital for chest pains. This came just four weeks after Beppe Sannino quit when his relationship with the players had soured.
But despite the upheaval, the Hornets have maintained a position in the top six and former Scotland international McKinlay, whose only experience as a manager has come through brief caretaker spells at Fulham, has been charged with keeping promotion aspirations alive.
His side dominated for large periods of the first half, with Ighalo heading against the bar, but home keeper Gomes had to be alert at the other end to tip over a rasping shot from Jota.
Ighalo scored the opener - and the first of his Watford career - when he went down under a challenge from James Tarkowski late in the first half and tucked in the rebound after David Button saved the initial penalty.
Mark Warburton's mid-table Bees are steadily adapting to life in the Championship following last season's promotion.
And their increased intensity after the break was rewarded when Alan Judge slid in Douglas, whose drive found the corner of the net, despite Gomes getting a hand to it.
Vydra was on hand though in the 70th minute to latch on to a Brentford clearance and thunder a 20-yard strike into the roof of the net for his fourth goal since returning to the club this summer.
The Bees pushed for the equaliser, although amid the late drama Lloyd Dyer had a chance to finish off the game but his point-blank effort was blocked by Button.
Pudil was shown a second yellow card for hauling down Andre Gray in injury time.
Watford head coach Billy McKinlay:
"I was very, very pleased. I'm delighted to be in charge, I'd be exaggerating a little bit if I said I enjoyed it that much.
"There are bits and pieces to work on. But overall I'm really happy.
"It's important you pick up results consistently, that's the key in this league. You want to build a bit of momentum.
"Yesterday was hectic. I told the players the most important thing was their focus. These things happen in football and I wanted them to cut away the sideshow. I think they did that really well."
Brentford manager Mark Warburton:
"It was a magnificent shot from Vydra and there is nothing you can do about that.
"What changed the game was that shocking penalty decision.
"The Watford player is running into the box, Tarkowski is running alongside him, his hands are up and the player goes straight to ground. There was no contact whatsoever.
"Our players are distraught in there. I hate to come across as having sour grapes because it is not that at all. The fact is my players and our 2,000 fans were fantastic tonight and deserved at least a point."
- 14ParedesBooked at 90mins
- 18PudilBooked at 90mins
- 19FabbriniBooked at 51minsSubstituted forAnyaat 58'minutes
- 24IghaloBooked at 43minsSubstituted forAbdiat 74'minutes
- 20VydraSubstituted forHobanat 90+4'minutes
- 12McCormackBooked at 90mins
- 26TarkowskiBooked at 43mins
- 20DiagouragaSubstituted forProschwitzat 79'minutes
- 23JotaSubstituted forPritchardat 69'minutes
- 22Alves Coelho
- Graham Salisbury
- Shots on Target
Second Half ends, Watford 2, Brentford 1.
Attempt saved. Lloyd Dyer (Watford) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Gianni Munari with a headed pass.
Corner, Watford. Conceded by David Button.
Attempt missed. Ikechi Anya (Watford) right footed shot from the left side of the box misses to the right. Assisted by Craig Cathcart following a fast break.
Alan McCormack (Brentford) is shown the yellow card for a bad foul.
Foul by Alan McCormack (Brentford).
Almen Abdi (Watford) wins a free kick on the left wing.
Attempt blocked. Lloyd Dyer (Watford) left footed shot from outside the box is blocked. Assisted by Ikechi Anya.
Attempt saved. Jake Bidwell (Brentford) header from the centre of the box is saved in the bottom left corner. Assisted by Alex Pritchard with a cross.
Substitution, Watford. Tommy Hoban replaces Matej Vydra.
Second yellow card to Daniel Pudil (Watford) for a bad foul.
Andre Gray (Brentford) wins a free kick on the right wing.
Foul by Daniel Pudil (Watford).
Juan Carlos Paredes (Watford) is shown the yellow card.
Corner, Brentford. Conceded by Juan Carlos Paredes.
Hand ball by Gianni Munari (Watford).
Attempt saved. Ikechi Anya (Watford) left footed shot from a difficult angle on the left is saved in the centre of the goal. Assisted by Lloyd Dyer.
Corner, Watford. Conceded by Tony Craig.
Attempt blocked. Ikechi Anya (Watford) right footed shot from the right side of the box is blocked. Assisted by Matej Vydra.