Oxford United dropped out of the League Two play-off zone as Peter Murphy's equaliser earned Accrington a point.
Dean Winnard's header hit the inside of the post for Stanley, only for Wes Fletcher to be judged offside when he tapped in the rebound from close range.
But Paul McLaren put the U's ahead on 35 minutes when his deflected 25-yard free-kick wrong-footed Sean Murdoch.
Oxford keeper Ryan Clarke made saves from Fletcher and Kevin Long but was beaten by Murphy's 20-yard leveller.
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Oxford United manager Chris Wilder told BBC Oxford:
"Ten games into the season, four points off the top, two off the play-offs, it's a steady enough start for us.
"We can be better, we know we can be better. It's a bit of a turnaround this year that we are winning away and drawing at home.
"Overall I think a draw is a fair result in the game considering the amount of chances they had and the amount of play we had."