Eurosport - Mon, 03 May 19:08:00 2010
The Gunners made a menacing start to the match, with Theo Walcott showing his blistering pace to keep the ball in on the far right and square the ball to Vela with an open goal to aim at.
The 21-year-old Mexican looked certain to score, but his effort screwed horribly wide of the Paul Robinson's far-post, and Blackburn could count themselves lucky to remain level with just four minutes played.
Arsenal made no such error 10 minutes later, with the fit-again Van Persie meeting Bacary Sagna's flick-on from a corner at the far post to head the Gunners into a deserved lead.
However, with the advantage secured, Arsenal's attacking vigour wilted, and Sam Allardyce's tactics came sharply into focus.
Rovers unleashed a barrage of long balls to repeatedly test Lucasz Fabianski, and would eventually force the breakthrough on the brink of half-time.
Fabianski flapped at a corner, under immense pressure from a host of Rovers players, and the ball eventually dropped to Keith Andrews, who picked out Dunn to tap in at the far post.
With the sides level at half-time, Blackburn would emerge for the second half looking far more threatening than their illustrious guests.
Dunn played a lovely ball through to Morten Gamst Pedersen, whose shot was well parried by Fabianski, and as the rebound fell kindly for the Norwegian to regain possession right on the touchline, Sol Campbell scythed him down with a clumsy tackle from behind.
The referee waved on the Blackburn penalty appeals, and would do the same to Arsenal 10 minutes later, as Michel Salgado bundled over Van Persie inside the area.
With Dunn and Pedersen repeatedly testing the creaky Campbell and Silvestre, a second Blackburn goal began to look increasingly inevitable.
A 67th minute corner was swung in to the Arsenal goalmouth, and again Fabianski failed to punch clear.
Samba headed the ball emphatically into the net from two yards out, to seal a deserved win for his pragmatic side, but also raise serious questions about the ability of Fabianski to physically command his area.
The defeat leaves Arsenal looking worriedly over their shoulder, with Tottenham still in the hunt for third place, five points down with two games to play.
The win for Blackburn means they have successfully avoided defeats against the old 'big four' at Ewood Park this season, and once again Allardyce has proved to be a thorn in Arsene Wenger's side.