Defiant Scunthorpe bounced back to prove themselves Oxford's toughest opposition so far this season.
Playing attractive, possession football they dominated for long spells against the side their manager Brian Laws described as 'the land of the giants'.
But they were a goal down two minutes before half time.
Jamie McCombe appeared to clear a corner with his head, but referee Mike Ryan of Preston, had spotted an innocuous challenge by defender Nathan Stanton on Steve Basham, even though the player was nowhere near the ball.
Oxford skipper Andy Crosby made no mistake from the spot.
The decision left Laws bemused: "The referee was the only one on the park who saw the penalty," he said.
"Apparently it was a shirt-pulling offence. If that's the case, there should have been at least ten penalties this afternoon.
"Even the Oxford players didn't know anything about it. I'm very disappointed to have drawn a game by conceding a goal like that." Oxford manager Ian Atkins was like so many visiting managers at Scunthorpe's Glanford Park, full of praise for the opposition they met.
He admitted his players could have done better and certainly needed more stamina in midfield.
"But Scunthorpe are very well organised and grind you down. They're a side to watch," he said.
And no-one needs more watching than Scunthorpe's former skipper, the veteran Peter Beagrie.
Atkins knows the player is in his late 30's and is the one that will always cause the most danger. "He does very well in this Division, and we just couldn't keep up with him," he said.
Beagrie's 63rd minute equaliser illustrated the point perfectly.
As usual, Beagrie was working hard on the left. Twisting and turning like an eel he shrugged off several Oxford players and made himself the space in which to try a shot.
The angle was acute, Beagrie was outside the area and no more than a dozen yards from the by-line.
The ball curled out of reach of the despairing dive of Andy Woodman in the Oxford goal and went in off the post.
And if Beagrie continues to play such inspired football Atkins will be proved right, Scunthorpe will indeed be the side to watch.