Stanley suffered a second successive loss as they were ruing missed chances at the Kassam Stadium.
Oxford were clinical in front of goal with James Henry and a Matty Taylor brace giving Karl Robinson’s men the three points in their promotion charge.
Stanley got into double figures for chances created but were unable to get enough on target and slipped down to 16th in the league.
The Reds started well, bossing the early stages and had a great chance to open the scoring after Joe Pritchard had a goalbound strike blocked, following good work from Jordan Clark.
However Oxford broke quickly in the 13th minute and Marcus Browne fed Henry to the right of the area and he fired home his 13th goal of the season.
Unmarked Bristol City loan striker Taylor headed over the bar for Oxford as the home side grew into the game but Stanley were still a threat, Sam Finley weaving his way into a good position to set up Colby Bishop but the defence managed to clear.
Stanley came close to equalising on the half hour mark when Clark’s looping header was hooked off the line by keeper Simon Eastwood. The ball fell to Dion Charles in the six yard box but his initial strike was blocked, the ball came back out to him but he fired over.
Oxford continued to break at pace and Ross Sykes did well to block a Henry ball in while unmarked Browne got the ball at the far post but his effort was deflected wide.
From the resulting corner, Taylor forced a superb save out of Joe Bursik and, in the last action of the half, Stanley’s Charles raced onto a ball but blasted over.
The home side doubled their lead on 48 minutes when Oxford once again broke quickly and Cameron Brannagan’s cross found Taylor in space and he fired home the second at the far post.
Bursik then produced a superb save, sticking out his leg, to deny Henry a third and he also pushed out a Browne 30 yard free kick.
Stanley still searched for a goal, Pritchard got the ball unmarked in the area but couldn’t connect properly and the Reds felt they should have had a penalty for handball but nothing was given.
John Coleman then changed it around bringing on Benny Ashley-Seal for Charles with 25 minutes to go.
However it was Oxford who struck next on 72 minutes when Henry’s cross in found Taylor who had got in front of the Reds defence and headed home his 16th goal of the season.
Defender Sykes wasn’t far off with a looping header and Ozzy Zanzala came on but the Reds were unable to get on the scoresheet.