The £10million former Tottenham striker grabbed a fifth minute winner to give the Black Cats their first victory at the Reebok Stadium in almost eight years.
Bent struck after just five minutes when he rose above Kevin Davies at the far post to head home Steed Malbranque's cross.
Kieran Richardson would have doubled Sunderland's lead on 20 minutes but for a fine save from Jussi Jaaskelainen.
Bent nearly grabbed his second less than 60 seconds later when his shot on the turn was just inches wide.
Kenwyne Jones then went close moments when he headed narrowly over the crossbar, before Jaaskelainen produced another good save to turn away Bent's low shot before scooping the rebound away from Malbranque.
Bent then lobbed wide on 40 minutes and Bolton would have gone in at the interval level but for an incredible reflex save from Marton Fulop to keep out Gary Cahill's header from Matt Taylor's corner on the stroke of half-time.
Taylor missed another great opportunity to equalise six minutes after the restart when he poked his shot wide from 10 yards after Johan Elmander had teed him up.
Elmander then fired over as Wanderers were at last showing some signs of life, though they received a let off moments later when Jones shot tamely at Jaaskelainen after being sent through on goal.
Davies' flick on from Paul Robinson's long throw nearly caught Fulop out but the goalkeeper recover to punch clear from under his own crossbar on 64 minutes.
Elmander then flashed a shot across the face of goal as Bolton piled forward in search of an equaliser.
Bent missed a late chance to wrap up the game when his shot was deflected onto the roof of the net and he would have been made to regret that but for a brilliant save from Fulop from Sean Davis deep into injury time.