Plucky Southampton looked to have condemned the champions – unbeaten in a record 49 league games until last Sunday’s defeat at Manchester United – to their second successive Barclays Premiership defeat with two headed goals from Rory Delap in the last 10 minutes.

Thierry Henry had put Arsenal in front when he atoned for a first-half penalty miss by slotting home from close range in the 66th minute.

But Delap scored two superb headers in the 80th and 85th minutes to put the Saints in front, and their amazing comeback forced Arsenal to surge forward for a leveller.

That arrived 30 seconds from time when van Persie, who scored his first goal for the club at Manchester City in the Carling Cup in midweek, sent a curling shot into the top corner from eight yards to the relief of the Arsenal faithful.

The delight was doubled when news of Manchester United’s defeat Portsmouth was read out over the tannoy system on the final whistle.

Henry had missed a first-half penalty as Arsenal struggled to cope with a resolute Southampton defence.

The Gunners dominated the opening period but could have found themselves a goal down in the 20th minute when the Saints, in a rare attacking moment, saw the woodwork come to Arsenal’s rescue.

Mikael Nilsson got free on the right and his angled drive beat the outstretched Jens Lehmann and looked set for the bottom corner.

But as the Southampton fans prepared to celebrate what would have been a shock lead, the ball cannoned back off the right-hand upright and away to safety.

Southampton rarely threatened in the opening quarter as Arsenal’s quickfire attacking and possession game denied them any real opportunities to go forward.

In the 17th minute, Southampton’s frustration at not being able to get the ball culminated in a yellow card for Paul Telfer for a foul on Jose Reyes.

In the 28th minute Arsenal were awarded a penalty when full-back Darren Kenton could not cope with Dennis Bergkamp’s trickery and felled him inside in the penalty area. However, Henry saw his spot-kick cannon back off Antti Niemi’s left-hand upright to keep the scores level.

The champions again took the game to their visitors in the second half and Bergkamp was unlucky not to make Claus Lundekvam pay for a poor clearance just three minutes after the restart.

Bergkamp found Henry inside the penalty but the Frenchman could not produce a quality cross and had to settle for a corner which came to nothing.

In the 61st minute, Gunners boss Arsene Wenger clearly decided more impetus was required and when Reyes collected a hand injury, he opted to introduce Robert Pires.

Arsenal’s frustration was further epitomised a minute later when captain Patrick Vieira was booked for a challenge on Telfer.

Arsenal finally broke the deadlock in the 66th minute with Henry atoning for his first-half penalty miss.

Bergkamp’s glorious 30-yard lofted pass found Henry in space just behind the Saints defence. As the visitors appealed for offside, the French striker effortlessly brought the ball under control and slotted it beyond Niemi and into the corner of the net.

In the 78th minute, Arsenal should have added another but Freddie Ljungberg somehow failed to convert Henry’s cross after the Frenchman has left the Southampton defence trailing in his wake down the left flank.

Ljungberg was unmarked on the edge of the six-yard box but his weak shot was parried to safety by Niemi.

Two minutes later Arsenal were made to pay for their costly errors in attack when Telfer’s corner on the left-hand side was met with a bullet header from Delap.

But Wenger’s side came storming back and Henry created a simple chance for Pires in the 82nd minute but once again their poor finishing cost them.

Henry’s cross found Pires in space just six yards out but his French team-mate miskicked the ball and Niemi made an easy save.

With seven minutes left Wenger made his final change in a bid to find a late winner.

Van Persie replaced Ljungberg but the Gunners still had more defending to do in the meantime.

They failed to do that adequately in the 85th minute when Delap scored his second header. A cross from Neil McCann was met at the near post by Delap and his flicked header soared past the stationary Lehmann.

But Arsenal saved themselves – and preserved their place at the top of the table – when van Persie sent a stunning shot into the top corner in the dying seconds of added time.