A weakened Arsenal knocked Manchester United out of the cup at Old Trafford with Edu's deflected free-kick and Sylvain Wiltord's goal decisive.

Fabien Barthez was blameless as Edu's 34th-minute set-piece took a cruel deflection off the shoulder of David Beckham, so when stand-in striker Wiltord netted a fine goal early in the second half the match was all but over.

The eagerly-awaited FA Cup fifth-round clash began in fiery fashion, as Paul Scholes hacked down Patrick Vieira, Sol Campbell knocked down Ole Gunnar Solskjaer and Ruud van Nistelrooy lunged at Martin Keown and then clattered with Lauren in a brutal opening few minutes. Scholes, van Nistelrooy and Vieira were all booked for their various parts in the melee.

When the brawling died down and the football began, United almost broke the deadlock on 12 minutes as Solskjaer raced down the left and smashed a low shot off the post.

On 30 minutes came what should have been the breakthrough, as last-man Keown raced out and totally missed the ball leaving Giggs one-on-one with David Seaman. The Gunners keeper hesitated, Giggs challenged and the ball fell kindly to the Welshman in front of the open goal, only for him to curl his shot over the bar.

And then, in hugely fortunate circumstances, the Gunners broke the deadlock as Edu's free-kick from 20 yards smacked off Beckham in the United wall and gave Barthez no chance as it looped into the top-left corner.

First-half chances all but dried up after that, but six minutes into the second half came another Gunners goal. Edu's clever through-ball on 51 minutes left Wiltord with a lot to do but his first-time touch beat the last man and he rolled the ball firmly past Barthez for a deserved two-goal cushion.

Arsenal should have scored again with 11 minutes to go as Henry, on from the bench, released Wiltord down the middle to bear down on the United goal. But his French team-mate dallied in front of Barthez as Wes Brown recovered from poor positioning to get in a late tackle that just about saved an even greater deficit.