Ryan Lowe was Bury's hero as he grabbed the winner for the Shakers to set up a 2-1 win over Oxford.
Lowe received a pass from midfielder Andy Howarth before taking a step and then stroking the ball comfortably past goalkeeper Ryan Clarke with 11 minutes remaining.
Both sides grabbed a goal apiece in an entertaining first half at the Kassam Stadium.
Asa Hall had an early shot saved by Bury keeper Cameron Belford, but it was the visitors who opened the scoring in the 26th minute, when Tom Lees rose to head home Peter Sweeney's cross.
Within five minutes the U's were level. This time Hall was the provider as he crossed for Jack Midson to strike home a crisp shot from inside the box.
Oxford's James Constable twice went close for the hosts either side of Lowe's winner, but in the end the Shakers held on for a deserved three points.