Ray Harford, in his first match in charge, saw his Rangers side concede a goal in the third minute and although they equalised, the Londoners were eventually destroyed by Joey Beauchamp.
The winger set up the opening goal after Oxford skipper Mike Ford put him clear on the left, Beauchamp's perfect cross being headed in by Nigel Jemson.
Rangers equaliser after 19 minutes came when a deep cross from Trevor Sinclair was volleyed in by the former Chelsea player Gavin Peacock.
But Beauchamp's pace and skill were a constant worry to QPR's defence, and he restored United's lead after 36 minutes.
Martin Aldridge found him on the left and after cutting inside Mark Parry, he drew Tony Roberts off his line and sidefooted the ball into the far corner.
Four minutes after half-time a bad tackle by Karl Ready on Jemson was punished by Oxford's third goal. With Beauchamp again in possession after the foul, the referee played advantage and the winger ran through unchallenged before superbly chipping over Roberts.
The Oxford manager, Denis Smith, heaped praise on Beauchamp but admitted he may have to sell the player, who had an unsuccessful spell with West Ham in 1994 before he returned to his home-town club via Swindon.
The First Fivision club were recently forced to make their entire squad open to offers after admitting to debts of around pounds 10m.
"I need to have offers for players before I sell them. We'll make decisions as a board whether we need to sell them or not," Smith said. "There's been a lot made of our position and, yes, we are in a position - that a lot of other clubs are in - that we have got no money and could do with a little bit more.''
Oxford Utd: Whitehead, Gray, Ford, Robinson (Remy, 90), Purse, Gilchrist, Massey, Smith, Aldridge (Banger, 67), Jemson, Beauchamp. Substitute not used: Angel.
QPR: Roberts, Perry (Maddix, 79), Brevett (Brazier, 79), Murray, Ready, Yates, Spencer, Peacock, Quashie, Sheron, Sinclair. Substitute not used: Barker.
Referee: T Heilbron (Newton Aycliffe).Reuse content