Gainsborough Trinity failed to build on the good result at Harrogate Town after a late Mark Preece goal gave Oxford City all three points at Marsh Lane on Thursday night.
In a game that seemed destined to end goalless, Preece headed home three minutes from time to give the strugglers their second successive victory.
Trinity went in to the game on the back of a battling draw at Harrogate and looked threatening throughout with Jonathon Margetts shooting wide from 20-yards.
The Hull Loanee went close to adding to his six goals for the club again moments later as he forced Matt Bulman into a good save in what was an even game.
Greg Young then went close but he headed Simon Russell’s free kick straight into the hands of Bulman.
After the break Margetts threatened again followed by Darren Mullings for Oxford in a half of very few clear-cut chances.
But as Trinity failed to find a breakthrough, Oxford struck on 87 minutes to keep Steve Housham’s side in the relegation fight.
With time running out, Preece rose highest to nod home Michael Pook’s free-kick past Phil Barnes to snatch all three points.
Oxford City: Bulman; Benjamin, Learoyd, Preece, Stonehouse; Mceachran (Soloman-Otabor), Mullings, Pook, Pond, Winters (O’Hanlons); Basham (Symons)
Subs not used: Wilmott, Jackson
Gainsborough Trinity: Barnes; Roma, Lacey, Leary, Young; Roberts, Russell, Davie (89’ Stamp), Davis (55’ Wooton); Bateson (69’ Toner), Margetts
Subs not used: Martin, Wooton, Williams
Referee: Mr S. Plane