JOHNNY Mullins's strike in the sixth minute of stoppage time preserved Oxford United's unbeaten start to the season.
The U's lost their 100 per cent record, but were staring at a defeat to ten man Wycombe Wanderers as Dean Morgan returned to haunt his former club with two goals.
Morgan headed Wycombe in front at the end of a poor first half where the hosts had struggled to get going.
The game was turned on its head early in the second half when Charles Dunne was sent off for an elbow on Alfie Potter.
From the free-kick Danny Rose scored his second of the season and it looked as if the hosts would go on to control the game.
But Morgan won and converted a penalty to put Wycombe ahead once more.
The hosts huffed and puffed but could not break down the visitors, until Mullins popped up with an equaliser deep into stoppage time.
It was enough to keep Chris Wilder's side top of the Sky Bet League Two table on goal difference.
United made two enforced changes, with a tight hamstring ruling out top scorer Deane Smalley.
New father James Constable came in for his first league start of the season, while Asa Hall replaced Sean Rigg (hamstring).
United came into the game with a perfect league record and almost got away to a good start.
Less than four minutes were on the clock when a Tom Newey long throw was only cleared as far as Scott Davies. The midfielder struck his low shot cleanly from the edge of the box, but it was straight at goalkeeper Matt Ingram.
It turned out to be the clearest chance the home side created in a disappointing first half.
United were unable to build up any sustained pressure as Wycombe's back four, led by skipper Gary Doherty, looked solid.
The visitors had lost their last two league games, but grew in confidence as the half wore on.
Morgan was a nuisance to United's defence and only a deflection took a volley from the forward over on 16 minutes.
United were below par and Ryan Clarke was almost caught out just after the half hour mark when Steven Craig charged down his clearance. To the goalkeeper's relief the ball rebounded harmlessly for a throw-in.
The hosts looked like they needed to get in and regroup at the break, but three minutes before the interval Wycombe took the lead.
A ball into the box from Doherty was flicked on by Billy Knott and Morgan was the first to react, heading into the net from close rage.
It almost got worse for United on the stroke of half-time.
Clarke came out for a cross and punched straight to Nick Arnold 30 yards out.
The midfielder's lob was precise, but the backpedalling goalkeeper did superbly to catch and then throw the ball clear just before crossing the line.
Dave Kitson replaced Davies at the break, instantly giving United a more attacking outlook.
The game spun on two incidents four minutes after the break.
First, Dunne was sent off for an elbow on Alfie Potter, who had been switched out to the flank to accommodate Kitson.
Rose curled the resulting free-kick into the box, where it missed everyone and nestled into the corner of the net.
Ryan Williams was brought on to give United an added option going forward as the hosts looked to take advantage of their man advantage.
They looked a side transformed and Kitson narrowly headed wide from Potter's cross.
But out of nowhere Wycombe restored their lead.
David Hunt dived in on Morgan in the area and although the forward's tumble was theatrical, it was an ill-advised lunge and referee Andy D'Urso pointed to the spot.
The former Reading youngster smashed in from 12 yards for his second goal of the afternoon.
It gave United half an hour to find a way back into the game for a second time.
Kitson steered a cross from Newey over the bar, while even Johnny Mullins joined the attack at one stage to bring a smart save from Ingram.
Wycombe looked to slow the game when they could and were briefly down to nine men at one stage while Leon Johnson was off the pitch following a lengthy spell of treatment on it.
As the minutes ebbed away Kitson looked the most likely to grab an equaliser. The striker came agonisingly close to opening his United goalscoring account eight minutes from time with a curled shot which Ingram turned round the post at full stretch.
It looked a lost cause, but seven minutes of stoppage time gave hope of a late flourish.
The breakthrough came with just over 60 seconds remaining, when Constable did well from a Rose cross to give Mullins space and the centre back coolly finished to salvage a point.
Oxford Utd: Clarke, Hunt, Mullins, Wright, Newey, Davies (Kitson ht), Whing, Rose, Hall (Williams 52), Potter, Constable.
Unused subs: Crocombe, Raynes, Marsh, O'Dowda, Ruffels.
Wycombe: Ingram, McCoy, Doherty, Johnson, Dunne, Arnold, Knott (Spring 88), Scowen, Wood, Morgan (Kuffour 75), Craig (Pittman 69).
Unused subs: Harrison, Stewart, Kretzschmar, McClure.
Referee: Andy D'Urso (Essex).
Attendance: 7,100 (988 visitors).