It is as well that Sir Alex Ferguson has stopped speaking to the press otherwise he might have asked reporters to pardon his French here yesterday following Manchester United's fourth Premiership defeat of the season.

Not that the silent knight is likely to have felt like pardoning his French goalkeeper, that intriguing mix of the gifted and the gormless which is Fabien Barthez. Two late mistakes by Barthez - the first a howler, the second more forgiveable - handed Arsenal a victory which their now-familiar profligacy near goal appeared likely to deny them.

Add in the equally culpable error by Gary Neville which enabled Arsene Wenger's team to draw level early in the second half,after being frustrated by United's discipline for much of the first, and clearly the malaise which has affected so many of the champions' peformances this season is starting to acquire a look of permanency.

United remain out of the top three and while this hardly represents a crisis with 25 games to go, the inability of the team to hold leads must be giving Ferguson at least a metaphorical headache. Last Tuesday United would have won in Munich in the Champions League but for the late slip by Mikael Silvestre which enabled Bayern to force a draw.

Barthez's casual approach to goalkeeping overtook him when Deportivo La Coruna won 3-2 at Old Trafford just over a month ago and yesterday one of his blunders was just as blatant. Fore and aft of these lapses he saved expertly from Thierry Henry among others, yet Arsenal's French striker still finished with a couple of goals.

Arsenal's second home win of the season in the Premiership was a reward more for attacking persistence than any dramatic improvement in the haphazard finishing which previously had seen Wenger's side lose or draw more winnable encounters than this one.

For half the match only the peerless authority of Patrick Vieira kept Arsenal going at all once Paul Scholes had given Manchester United an early lead, itself the result of a defender's error. Just before the quarter-hour, in United's first concerted attack, Ruud van Nistelrooy slipped a pass wide to Silvestre on the left. A slip by Lauren let the French defender through and in an imitation of the opening goal in Munich Silvestre's low centre was turned past Stuart Taylor by Scholes.

By half-time the contrast between the naff way United had defended in conceding three first-half goals at Tottenham and the assurance with which they were denying Arsenal a goal now could not have been greater. In the air the command of Wes Brown was absolute while Roy Keane was the Irish guardsman personified in front of United's back four.

It could be argued that, but for Gary Neville, Arsenal would have striven in vain, with Barthez emerging from the afternoon as hero rather than buffoon. The ball Neville tapped straight to Robert Pires in the 48th minute was more worthy of a Gary Glitter, Pires squared the gift to Fredrik Ljungberg and the Swede lobbed a shot beyond Barthez with the outside of a foot.

For a while thereafter Highbury suffered some familiar angst as Arsenal, while playing with increased verve and determination, continued to waste their chances. Henry sent in Kanu but only for Barthez to save. Then Henry exchanged passes with Bergkamp but still could not beat the United goalkeeper, who was a little fortunate to escape with only a caution following a petulant assault on Matthew Upson at a corner.

With nine minutes remaining United seemed to have survived Arsenal's best efforts. What they could not survive, however, was the worst of Barthez.

All he had to do was make a routine clearance from an area where he might otherwise have been taking a goal-kick. But after giving the ball a thoughtful tap he directed it straight to Henry, who gratefully put Arsenal in front.

"Give it to Barthez," chanted the gleeful Arsenal fans, and "Barthez is a Gooner!" Certainly Manchester United were goners once Henry had scored again with five minutes remaining.

A long, quick pass from Vieira sent the French striker clear of a now ragged defence. Barthez was quick to meet the danger but having grabbed the ball he failed to hold it, allowing Henry another simple goal.

Taylor, Arsenal's third-choice goalkeeper, was able to spend most his time studying his vaunted opposite number, and certainly Barthez offered an ample demonstration of what, and what not, to do.

ARSENAL: Taylor, Lauren, Campbell, Upson, Cole, Parlour, Vieira, Ljungberg, Pires (Grimandi 83), Henry, Kanu (Bergkamp 64). Subs Not Used: Wiltord, van Bronckhorst, Stack. Booked: Upson, Ljungberg. Goals: Ljungberg 48, Henry 80, 85.

MANCHESTER UTD: Barthez, Gary Neville, Blanc, Brown, Silvestre (Phil Neville 57), Beckham, Veron (Yorke 58), Keane, Fortune, Scholes, van Nistelrooy (Solskjaer 77). Subs Not Used: Butt, Carroll. Booked: Blanc, Barthez, Beckham. Goals: Scholes 14.

Referee: P Jones (Loughborough).