City failed to push on from an early goal from Nahki Wells, as Oxford came back to equalise through Sean Rigg and a controversial last minute penalty awarded for a foul on Alfie Potter by Stephen Darby was expertly dispatched by Peter Leven to condemn The Bantams to yet another disappointing league performance and result.
Oxford looked to test Matt Duke early on and after Liam Davis' run and pass, Sean Rigg forced Duke into a smart save when he tried his luck with a shot from 18 yards.
A long ball forward from The Bantams allowed Nahki Wells to hunt down Michael Duberry, a lapse in communication between Duberry and United keeper Wayne Brown was followed by Duberry heading the ball past Brown, as the ball looked to be going behind for a goal kick Wells nipped in to tap the ball home and give City an early lead.
Oxford were back on terms within 5 minutes of the opening goal; Alfie Potter's cross into the area was half cleared as far as Sean Rigg who lashed a superb half volley into the bottom corner beyond Matt Duke to give his side a stunning equaliser.
Gary Jones tried to catch Wayne Brown off his line with a looping shot from the edge of the area but Brown stood his ground well enough to hold the ball at the second attempt.
Well known in the lower divisions for his ability from set pieces, Peter Leven had a chance to put this to the test when a freekick was awarded 20 yards from goal. His dipping shot beat the wall but Duke was equal to the strike and made an alert save.
Damian Batt escaped the attentions of debutant full back Ryan Dickson to produce a cross, the delivery was met by the head of Michael Raynes but the header lacked power and was comfortably gathered by Duke.
Gary Jones' freekick was headed into the air by Michael Duberry ahead of Rory McArdle and the ball fell to Will Atkinson who hit a rising shot over the bar from the edge of the area.
Lewis Montrose carved City open with an unchallenged run down the middle of the pitch, he was closed down as he looked to find an opening for a shot and he played the ball wide to Alfie Potter whose powerful angled drive forced an acrobatic save from Duke.
Gary Jones found Zavon Hines with a pass early in the second half but he continued to fire a rising shot a few yards over the bar.
Rory McArdle's attempted clearance was charged down by Sean Rigg who tried to catch Duke out with an early low shot but he got down well to push the ball alertly behind for a corner kick.
Chris Wilder's men were pressing and looking the more likely to score the next goal; Damian Batt's cross was headed downwards and towards goal by Potter, Duke got something on the ball but Carl McHugh had to clear off the line to deny the visitors.
Batt managed to deliver yet another cross which was this time behind a couple of onrushing blue shirts but Liam Davis made something of the cross by hammering a first time shot towards goal which forced Matt Duke into a smart save.
Peter Leven's corner minutes later fell kindly for Sean Rigg whose header came back off the underside of the bar and was cleared to safety by Carl McHugh.
Oxford were pressing for a late winner and they were awarded a controversial penalty by referee Jeremy Simpson in the last minute of the 90. Alfie Potter looked to get away from Stephen Darby inside the area who stretched to make a challenge. Whether he got some of the ball remains to be looked at again but Potter went down in a heap and a spot kick was awarded. Leven made no mistake from 12 yards as he buried his effort into the roof of the net, straight down the middle, leaving Duke with no chance.
The Bantams thought they'd equalised in the second minute of injury time. Gary Jones' freekick was flicked on by McArdle and bundled home by McHugh but the flag went up against McHugh for offside to leave the City faithful disappointed at another pointless outing.