Oxford delivered a stunning second-half showing to snap a three-match losing streak with a 4-1 success at Peterborough.
The visitors found themselves behind to a goal from joint League One leading scorer Jack Marriott after a quarter-of-an-hour.
Marriott raced onto a defence-splitting Anthony Grant pass to prod the ball past Oxford goalkeeper Simon Eastwood to register his ninth goal of the campaign.
But Posh were brushed aside in the second period as Pep Clotet's men ran riot with midfield ace Jack Payne creating all four goals.
He laid on a 48th-minute leveller for Josh Ruffels with a fine cross from the right and slipped in Wes Thomas to complete a quick turnaround five minutes later.
Payne was again the architect, along with James Henry, when Joe Rothwell extended the advantage with 15 minutes to go.
And substitute Agon Mehmeti put the result beyond doubt with seven minutes to go when tapping in after a Payne shot was saved.
Marriott headed against the bar late on but Posh had already been condemned to a second-successive defeat by then.