Lauren and Villa's Gareth Barry challenge at Highbury (ShaunBotterill/Allsport)

But for 45 error-prone and self-doubting minutes, they made a mockery of their recent brilliance against Manchester United and Juventus and went in two down at the break.

Arsenal knew that Liverpool and Leeds United had won and that Sir Alex Ferguson's champions had lost further ground. But any impetus they might have enjoyed from Arsene Wenger signing his new contract appeared to have been lost.

Villa were in control all over the field, pressing and hassling Arsenal into giving away possession and territory while converting two chances.

There were memories of a different era after 21 minutes when Paul Merson, once one of Highbury's favourite sons, showed he has lost neither his appetite for, nor the knack of, scoring important goals.

While Wenger's side had been failing to make much of an impression with their familiar pattern of passing round opponents, Villa goalkeeper Peter Enckelman opted for the most direct route with a massive punt upfield.

Dion Dublin was more aggressive in his aerial challenge with Sol Campbell and Matthew Upson reacted slowly to Merson's presence on his shoulder. Before Upson could recover, the old campaigner had raced away and chipped Stuart Taylor to open the scoring.

With George Boateng commanding the midfield despite the fragility of Lee Hendrie beside him, Villa were comfortable throughout and soon exploited Arsenal's uncertainty further.

After 34 minutes, Steve Staunton swung a long ball to the edge of the box which Lauren inexplicably headed towards his own goal.

Campbell did what he could with an unexpected clearance header but Alan Wright quickly collected and fed Hendrie.

Dublin's return to Hendrie was as flamboyant as it was effective and when the ball arrived with Steve Stone, he drove it under Taylor.

The gloom that greeted Villa's second goal deepened further when Vieira was cautioned before half-time, ruling him out of the showdown with Liverpool at Anfield in a fortnight.

Wenger looked more puzzled than angry as he retreated for the interval and his immediate response was to introduce Martin Keown and Sylvain Wiltord, who clawed Arsenal back into contention with minutes of his arrival. The consistently excellent Ray Parlour took a reverse pass from Robert Pires and crossed for Wiltord to volley home.

J'Lloyd Samuel should have put the game beyond Arsenal's reach after 65 minutes when he evaded Keown only to shoot wide of the far post. Having been granted the stay of execution, Arsenal became more direct and began playing Villa at their own game.

Vieira's towering presence put Samuel under pressure and he saw enough of the ball to steal it and quickly centre for Thierry Henry. One touch to control and another to dispatch was all that was needed to put things level.

With 18 minutes left, all bets were on Arsenal winning it but it took them slightly longer than the regulation 90 to seal the crucial victory. Enckelman kicked short to Ashley Cole, who supplied Pires. Henry timed his run to perfection, evaded the offside trap and rolled his shot under the goalkeeper.

Merson later condemned his side's defeat as: 'Schoolboy stuff that I wouldn't see in one of my son's games in the under nines'.

Maybe so, though Arsenal at least appeared to have learned their lesson about the importance of winning home matches when you're chasing the Championship.

Wenger said: 'Our tremendous energy and desire won us through and we need to retain this winning mentality. This will strengthen our belief that we can do it.'

Henry, who took his season's tally to 21, added: 'This is the kind of game which we would have lost earlier in the season. But now we will fight to the end.'