Oxford manager Chris Wilder saw his wholesale changes pay-off after a fine 2-1 win at Port Vale.
Wilder made seven changes after three straight defeats and came up trumps as Harry Worley netted a second-half winner.
Jack Midson squandered two excellent early chances for the fired up visitors before Vale made the breakthrough following a 27th-minute penalty.
Tom Pope was pushed to the ground by Ben Purkiss and Marc Richards put away the rebound after Ryan Clarke had dived to block his spot-kick.
Oxford were gifted a 33rd-minute equaliser when Chris Martin fumbled Alfie Potter's long-range shot against the crossbar and Midson tapped in the loose ball.
Martin, who was guilty of another poor error against Stevenage last month, paid the price for his gaffe when he was replaced by Stuart Tomlinson at half-time.
But Tomlinson had no chance when centre-half Worley gave Oxford the lead 13 minutes into the second period.
Josh Payne's shot was deflected into the path of Worley who smashed an angled drive across Tomlinson and into the far corner of the net.
Vale boss Jim Gannon bolstered his firepower with Louis Dodds and Justin Richards coming off the bench, but the visitors held firm for a deserved victory.
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