James Constable came off the bench to inspire Oxford to a 2-1 victory against Barnet at the Kassam Stadium in one of the few lower division games to beat the freeze.
United's top scorer forced Bees centre-half Anwar Uddin into an own goal as he challenged hard for the ball against goalkeeper Jake Cole in the 63rd minute.
And then Constable completed Oxford's comeback by drilling a low shot inside Cole's left-hand post from 16 yards with seven minutes remaining - his ninth goal of the season.
Barnet had led through Mark Marshall, who side-footed home from 16 yards after George Francomb and Kevin Gallen had worked the ball across the box.
The defeat leaves Barnet still looking for their first away win of the season, but it was Oxford's second successive victory after they had trailed at half-time, following last week's shock win at league leaders Chesterfield.