Jermaine Easter's 81st minute penalty was enough to secure victory for the home side in an entertaining encounter that saw both sides hit the woodwork and Brentford midfielder Sammy Moore sent off for two bookable offences.
Easter, who was linked with a move to Plymouth during the transfer window, missed a guilt edged chance to give the home side the lead in the 21st minute. Brentford skipper David McCracken headed down Martin Bullock's corner and Easter smashed the ball against the underside of the bar when it looked easier to score.
Brentford almost made him pay ten minutes later - defender Karleigh Osbourne crashing a header against the Wycombe crossbar from Glenn Poole's in-swinging cross.
They went close again on the stroke of half time, this time Ricky Shakes latching onto a half cleared corner, but his strike from the edge of the box whistled past home keeper Jamie Young's right hand post.
The turning point of the match came in the 74th minute. Moore appeared to be clipped from behind by Wycombe substitute Sergio Torres, but referee Andy Hall deemed the incident to be a dive and promptly showed Moore a second yellow card.
Wycombe made the extra man advantage count with ten minutes left when Bullock jinked into the box and was promptly upended by left back Grant Basey. Easter put his earlier miss behind him to coolly dispatch the spot-kick past Brentford stopper Ben Hamer and claim the three points for his side.