Sub Louis Saha swept in an 86th minute equaliser to grab a point for Manchester United on a day when leaders Arsenal set a league record of 30 games unbeaten from the start of the season.
Thierry Henry had given Arsenal a 50th minute lead with a typically audacious strike.
The result extended the Gunners' advantage over second-placed Chelsea to seven points, while they stay 12 ahead of third-placed United.
Arsenal manager Arsene Wenger said: "The record shows our consistency. Overall it's a fantastic achievement, but the players are still disappointed that they didn't get three points." Gunners skipper Patrick Vieira added: "We were disappointed to concede such a late goal. When we're ahead with ten minutes to go, we expect to win.
"But we lost our momentum, United sent a lot of men up front and put us under pressure with long balls." Henry's goal brought the game to life after a cagey first half.
Freddie Ljungberg and Jose Antonio Reyes had gone closest for Arsenal. Eric Djemba-Djemba forced a flying save from Jens Lehmann and Roy Keane shot wide after Paul Scholes' sliced effort.
There seemed little danger as Henry picked up Reyes' pass 30 yards out. Instead, he hit a wickedly swerving shot which left keeper Roy Carroll bewildered as the ball flew past him.
United surrounded referee Graham Poll three minutes later after Ryan Giggs fell under Sol Campbell's challenge, but the referee waved away their protests.
Arsenal missed three chances to wrap up the points. Reyes failed by inches to reach Ljungberg's cross, the Spaniard was blocked by Carroll, then Ljungberg shot weakly after Robert Pires split the United defence.
The arrival of subs Saha and Ole Gunnar Solskjaer hugely increased United's threat as the Gunners defended deep.
The pair combined for the equaliser. Solskjaer slid a diagonal centre behind the Arsenal backline. Saha, arriving unmarked, picked his spot.
"It was a little lack of attention that cost us," said Wenger.
Van Nistelrooy headed straight at Lehmann in stoppage time, while Henry was wide with an even later chance after Lauren's break.
So the two teams head into next weekend's FA Cup semi-final showdown after draws in both this season's league meetings.