Rovers went into the game just three points above the League Two drop zone, but on this showing they should have little trouble surviving having romped past the division's form team, with Albion suffering their first defeat in eight.
Brunt side-footed home a Joe Anyinsah cross from the right to reward a bright Rovers start after just five minutes and the home side could easily have stretched their advantage in the first half at the Memorial Stadium.
O'Toole eventually made it 2-0 after 62 minutes, shooting home from six yards following a cross by substitute Ollie Norburn, and Richards was similarly placed to lash home an Ellis Harrison cut back eight minutes later.
Burton goalkeeper Stuart Tomlinson made two good saves from Tom Parkes in the space of a few first-half seconds and another Anyinsah cross was just beyond the reach of Brunt.
