Oxford made it three successive wins as they inflicted Leyton Orient's first home defeat of the season.

The Us scored after nine minutes with what was to be their only shot of the first half.

Andy Scott escaped down the left flank and beat goalkeeper Glenn Morris from a tight angle.

Orient took 35 minutes to test United goalkeeper Andy Woodman, who comfortably held a Gary Fletcher header.

Carl Hutchings should have equalised when he totally miskicked in front of goal as the home side got more into the game.

Oxford extended their lead after 56 minutes with captain Andy Crosby converting a penalty after Andy Harris had been adjudged to have fouled Scott.

Orient had plenty of possession in the last half hour but rarely looked like breaking down their well-organised opponents until Crosby scored an own goal in stoppage time.

Leyton Orient: Morris, Joseph, Smith, Miller, Harris, Hutchings, Brazier, Jones, Campbell-Ryce, Fletcher, Thorpe. Subs: Barrett, Nugent, Martin, Ibehre, Barnard.

Oxford Utd: Woodman, Crosby, Bound, Viveash, McNiven, Savage, Hunt, Oldfield, Powell, Scott, Ford. Subs: Whitehead, Ricketts, Omoyimni, Louis, King.

Referee: P Prosser (Gloucestershire).