Bury's record losing run extended to 12 games
Oxford came from behind to win 3-2 at beleaguered Bury and stretch their unbeaten run to eight.
The hosts twice went in front through James Vaughan and Tom Pope, only for each goal to be cancelled out by a Chris Maguire free-kick.
Greg Leigh's own goal on 70 minutes then extended Bury's club-record losing run to 12 league games, sending them into the League One relegation zone.
The Shakers dropped keeper Ben Williams for Paul Rachubka and the debutant's fifth-minute free-kick drifted over the Oxford defence for Vaughan to volley over Simon Eastwood.
The U's levelled eight minutes later, Maguire hitting a free-kick from the edge of the box into the bottom corner.
They were then firmly on top, with Maguire twice testing Rachubka before the veteran keeper parried a Robert Hall shot.
Maguire also sliced wide from eight yards and moments later Pope scored at the second attempt from Scott Burgess' 39th-minute cross.
This time Oxford took just four minutes to equalise, Maguire curling in a 20-yard free-kick.
The visitors had the better of a hard-fought second half as Kane Hemmings hit a post before left-back Leigh turned Marvin Johnson's low cross into his own net.