Manchester United slipped further behind Premiership leaders Chelsea after drawing with Arsenal at Highbury.
Defenders Rio Ferdinand and Wes Brown made superb blocks to deny efforts from Thierry Henry and Brazilian Gilberto.
Cristiano Ronaldo should have given United the lead just before the break, but he was guilty of a hurried finish.
Arsenal appealed for a penalty after a Gary Neville tackle on Cesc Fabregas, while late on Brown had a header cleared off the line after a corner.
As the game wore on Ruud van Nistelrooy came to the fore, but even the Dutchman was unable to break the impasse.
The draw left United trailing Chelsea by 13 points, while Arsenal now lag the Premiership leaders by a staggering 24 points.
So often this fixture has decided the destination of the title, but this result did little to alter the impression that Chelsea are destined to retain their Premiership trophy.
Arsenal probably had the better of the first-half, but after the hour mark United were the more dominant force.
The best of Arsenal's early counterattacks saw Robert Pires run almost the entire length of the pitch, but Gary Neville showed great defensive skill to clear the Frenchman's cross.
Arsenal also went close with several shots, notably Cesc Fabregas' precise effort and a Pires shot that Van der Sar pushed round the post.
A fixture that over the years has had its fair share of spiteful incidents drew a couple of yellow cards in the first half.
Ryan Giggs was booked for his challenge on Jose Antonio Reyes and just before the break Lauren was yellow-carded for a wild lunge at Ronaldo.
Wayne Rooney might easily have been sent off in the second half when having been booked for a challenge on Reyes he appeared to be guilty of deliberate handball.
Just before the interval Ronaldo really should have given United the lead.
Van Nistelrooy's quick feet provided him with space to blast a shot goalward, an effort so powerful Jens Lehmann could only push the ball into Ronaldo's path.
But with the goal at his mercy Ronaldo rushed his finish, blazing his shot over the bar.
Early in the second half Ferdinand came to John O'Shea's rescue when the Irishman's poor clearance feel to Henry.
The French striker unleashed a shot but Ferdinand threw his body at the ball to get in an important block.
Brown was just as alert in blocking a Gilberto shot following a Pascal Cygan flick-on.
In between those two Arsenal chances Ronaldo spurted down the Arsenal left, picking out Ryan Giggs who opted to shoot rather than pass to Van Nistelrooy.
On the hour mark Van Nistelrooy twice made his attacking presence felt, getting in a shot on goal after a Kolo Toure error and then the Dutchman almost reached a Ronaldo cross.
Van Nistelrooy also went close in a goalmouth scramble following a United corner.
With six minutes to go Neville's superbly timed run allowed him to latch on to Rooney's pass, but his shot rippled the Arsenal side-netting rather than the goal.
In stoppage time Emmanuel Eboue cleared a Rio Ferdinand header off the line.
Arsenal manager Arsene Wenger:
"I felt it was very close to a penalty on Fabregas when Neville tackled him from behind in the area."
"We wanted to win but it was a high pace and I felt both teams were always trying to have a break to get the other on the counter-attack.
"We can still improve but the team is on a good way at the moment."
Man Utd manager Sir Alex Ferguson:
"You have to be fair - it was their fourth game in eight days and the pace was relentless - a tribute to both sets of players.
"I think we had the better chances, but Arsenal had more of the possession, so a draw was probably a fair result.
"I think Ryan Giggs probably had our best chance, but the ball came out of the floodlights."
Arsenal: Lehmann, Lauren, Toure, Campbell, Cygan, Pires, Fabregas (Flamini 80), Silva, Hleb (Bergkamp 73), Reyes (Eboue 89), Henry.
Subs Not Used: Almunia, Senderos.
Booked: Lauren, Cygan.
Man Utd: Van der Sar, Neville, Ferdinand, Brown, Silvestre, Ronaldo, Fletcher, O'Shea, Giggs (Park 73), Rooney, van Nistelrooy.
Subs Not Used: Howard, Saha, Bardsley, Pique.
Booked: Giggs, Rooney, O'Shea.
Ref: G Poll (Hertfordshire).