Boro looked bright in the early stages and forced Brentford's 'keeper into three saves in the opening 12 minutes. Kaylen Hinds in particular caught the eye with his pace and trickery and will be disappointed not to have scored with his first chance which saw the Arsenal loanee go on a mazy run through the defence but fire over.
The visitors took the lead on 22 minutes through a fine free-kick, but Ryan Loft equalised on 38 minutes from the spot, after Hinds was fouled in the box.
The second half saw plenty of promising moments for both sides in an entertaining game, but it was Brentford who secured the win with a low drive on 88 minutes.
Kgosi Ntlhe, Kaylen Hinds and Ryan Loft all got valuable minutes for Darren Sarll's men whilst there was also a welcome return to action for Andrew Fox after injury. Seven scholars also featured in the game, including 90 minutes for both Zak Guerfi and Ben Wilmot.
Stevenage XI: Day, Kerr, Wilmot, Johnson, Ntlhe (Omar 71), Guerfi, McKee, Trialist (Fraser 46), Fox (Ofosu 71), Hinds (Georgiou 63), Loft (Cregan 71)