Bees striker Jordan Rhodes gave his side a dream start when he deflected home a shot from the edge of the area with just three minutes gone.
But Wycombe striker John Akinde levelled on 17 minutes when he rose above the Brentford defence to head home.
A David Hunt free-kick eluded the visitors’ defence midway through the first half to restore the Londoners’ lead before former Brentford midfielder John Mousinho volleyed Wycombe level just before the break.
Akinde, on-loan from Bristol City, put the visitors in front just minutes after the restart when he raced the length of the half before firing home across Bees keeper Ben Hamer.
But Sam Williams snatched a point for Brentford with a neat finish from 12 yards after Wycombe’s Tommy Doherty had been sent off for an alleged elbow on Hunt.