Barnet scored three goals in five minutes to end Oxford United's unbeaten home record.
The U's took the lead through Liam Sercombe after Barnet failed to clear a corner but the equaliser came when Curtis Weston scored with a low shot.
The Bees went ahead through John Akinde's close-range finish and Josh Clarke added a third just after the half hour with another low strike.
Sercombe pulled one back before Kemar Roofe spurned a chance to equalise.
Barnet manager Martin Allen told BBC Radio London:
Allen on Oxford v Barnet
"It was a very good performance from start to finish we looked dangerous.
"We put a plan together and we tried to play a bit on the counter-attack. We played extremely well and deserved to win.
"I just thought it was the right time to come here today and play them."
- Published20 June 2016
- Published7 June 2019
