The home side had full-back Gary Sawyer sent off for a second bookable offence 20 minutes from time and owed their draw to on-loan Reading keeper Andersen, who denied Myles Weston, Charlie MacDonald, Gary Alexander and Nicky Adams in Saturday’s League One stalemate at the Memorial Stadium.
Jo Kuffour forced the best save from Brentford’s Ben Hamer in the 38th minute with a low drive as two committed teams fought out an entertaining game.
Brentford will feel they should have won it having created most of the good chances. MacDonald fired over after controlling a Craig Woodman cross six minutes from time.
Rovers could have snatched it at the death when substitute Wayne Brown shot just over the crossbar after a good break from Kuffour.
But the last chance fell to the visitors when Weston cannoned high over the target in stoppage time.