Cheltenham let slip two important points in their bid to reach the play-offs as Oxford hit back to snatch a goal with a late equaliser in a 1-1 draw at the Kassam Stadium.
The Robins looked to be cruising to their second away win in four days after Steve Guinan had fired them in front after 54 minutes.
Guinan had earlier headed against the post and Oxford's team were struggling badly following two big injuries.
Goalkeeper Chris Tardiff had to leave the pitch after four minutes because of a badly gashed right arm following a challenge by Damian Spencer.
And centre-back John Ashton were stretchered off with a twisted knee before half time.
But Cheltenham were unable to get a second goal and they paid the price as Oxford were inspired by substitute Yemi Odubade.
The former Eastbourne Borough striker unsettled Cheltenham's defence with his speed and he began the run which lead to Steve Basham threading a pass through for Stuart Gray, who was tripped by Jerry Gill, which brought Oxford a penalty.
Basham stepped up to convert the spot-kick for his 12th goal of the season.
And Oxford almost snatched victory in the final minute when skipper Chris Hargreaves saw his header at a corner nodded off the line by Brian Wilson.