Oxford made it back-to-back league wins for the first time this season as they shocked Preston with a 3-1 win at Deepdale to move out of the relegation zone.
Michal Helik prodded the relegation-threatened outfit ahead in the fourth minute before Milutin Osmajic's 12th-minute equaliser.
Will Lankshear's improvised 54th-minute finish gave Matt Bloomfield's men a deserved lead and Ciaron Brown's header seven minutes later sealed the points.
Oxford jump up to 21st, ahead of Leicester and West Brom ahead of the weekend fixtures, while Preston are now five games without a win as their play-off hopes continue to disappear.
Paul Heckingbottom made a number of positional changes, including a shift to a back four with Andrew Hughes in an unorthodox left-back role, which perhaps explained their disjointed display against relegation-threatened opponents.
Preston's form has dropped off a cliff of late and they were stung early on here as Helik had to time chest down Cameron Brannagan's free kick and poke a finish past an exposed Dai Cornell as defenders just stood and watched.
Brown should have doubled Oxford's lead inside 10 minutes but headed wide and Preston soon made him pay as an unmarked Osmajic nodded past Jamie Cumming having landed on the end of a pinpoint Ben Whiteman delivery.
But the spirited visitors were not to be deterred and, within five minutes, Jamie Donley and Stanley Mills fired narrowly wide from just inside the box with Will Lankshear also seeing a goal-bound shot blocked by Lewis Gibson.
Callum Lang did keep Cumming's gloves warm with a 23rd-minute whipping free-kick after Osmajic was brought down by Brown - a reprieve from the visiting storm.
Eventually, the hosts did get a grip of the match - having a series of half-chances - but nearly fell victim to overplaying at the back after Donley seized on a loose ball and slipped Lankshear in on goal, who fumbled the opportunity with a poor first touch that allowed Cornell the chance to get his body in front of the attempted finish.
Oxford took the lead at the start of the second half with Lankshear diverting Stanley Mills' drilled strike from range into the corner following Ben Whiteman's half-clearance.
The U's were in dreamland and that dream began to soar just a minute after the hour as Brown got himself forward to emphatically head home a third, latching on to Helik's flicked header from Myles Peart-Harris' teasing long throw.
Brannagan already had an assist and smelled blood minutes on from the third goal, forcing Cornell into an awkward low save from 25 yards.
Jeers were ringing around Deepdale as the home faithful watched those in yellow run rings around players who were chasing a play-off spot not too long ago.
The managers
Preston's Paul Heckingbottom:
To follow...
Oxford's Matt Bloomfield:
To follow...