Barnet flew out the traps and how they didn't take the lead remains something of a mystery.
Having seen Adam Birchall spurn an early chance with a low shot from inside the box, the home side then managed to hit the woodwork twice within the opening 15 minutes.
Captain Ismail Yakubu headed against the post after Brentford failed to clear their lines from a corner, before Joe Devera repeated the trick as his near-post header also struck the same post.
Neal Bishop then went on a terrific surging run taking him past several players, although he was unable to hit the target from six yards out, while Birchall produced a tame shot at Ben Hamer in the visiting goal.
Brentford had hardly threatened, though still managed to take the lead against the run of play in the 36th minute.
Barnet claimed handball as they looked to play the ball into the Brentford box though as the referee waved play on, Glenn Poole and Alan Connell exchanged a neat one-two before the former drilled in a low shot past Rob Beckwith.
A goal to the good, they seemed to shoot themselves in the foot when just four minutes into the second period when Gary Smith needlessly picked up his second booking of the game for kicking the ball away.
Looking to make up with their numerical advantage, Kenny Gillet, Devera and Birchall all went close to levelling the score though could find no way past a stout Brentford backline.
However, they didn't take their chances and as if to rub salt in the wounds, Brentford doubled their lead with 17 minutes remaining as Poole coolly converted from the spot after Ricky Shakes was brought down in the box by Gillet.
Birchall pulled one back for Barnet two minutes into stoppage time and despite five minutes of time added on, they couldn't salvage a point.