The young Bees claimed the win with two goals from Max Haygarth, whilst Alex Gilbert notched the other as the side looked impressive on the day.
Neil MacFarlane’s side were boosted by the return of Fin Stevens and Alex Gilbert to the starting XI in a game they dominated for large parts.
It was one-way traffic from the off with Lewis Gordon’s cross in the first minute leading to a powerful attempt from Fin Stevens which was well blocked by the Watford back line.
Just five minutes later The Bees would have the lead when Haygarth got his first with a slice of good fortune with his curled free-kick coming off the wall, and with the keeper unable to react in time, the ball ended up in the opposite corner.
More high pressing from Valgeir Valgeirsson, alongside the ever-industrious Joe Adams, who played up front for the side in the absence of Aaron Pressley, saw both players have good chances but for the Watford keeper.
The good play was then stunted when Watford managed to get themselves level when they had a free-kick of their own just outside the box. A clever pass inside saw one of the Trialists initially denied by the onrushing Ellery Balcombe, but the rebound fell kindly for the Watford man who fired home from close range to make it 1-1.
The Bees continued to attack from set pieces with both Kane O’Connor and Tristan Crama going close with headers before the break- the Scot almost finding the net when his stooped effort was cleared off the line.
Brentford B kept going after the break as they dictated much of the play with Gilbert having a powerful low effort palmed away before Haygarth tried his luck but was denied by the keeper down to his left.
The second goal did come, though, when good play on the edge of the box saw Gilbert work the ball well to get some space before he prodded home to make it 2-1 with a clever finish.
Another chance would fall for Adams, but his effort lacked conviction, which preceded the first real attempt of the half from the hosts when one of their Trialists was played through on the right-hand side, and as he struck across goal, it was past Balcombe’s right-hand post.
A penalty would be awarded when the tricky Haygarth was brought down in the area 12 minutes from time before the on loan Manchester United man got up to convert the spot kick low past the keeper.
A professional final 10 minutes saw to it that The Bees would claim the 3-1 win as they will now look to build some momentum going forwards.
Watford U23: Trialist, Trialist, Stevenson, Wise, Perkins, Barrett, Trialist, Trialist, Trialist, Crichlow, TrialistSubs: Hutchinson, Trialist, Trialist, Trialist, Burchell, Lo-Everton
Brentford B: Balcombe, Stevens, Gordon, O’Connor, Valgeirsson (Hercules, 76) Gilbert, Adams, Trialist (Trialist, 80) Carre, Haygarth, Crama (Trialist, 86)Subs not used: J. Thompson, Koutsimouka, Trialist