The Gunners could have won by seven as they were driven by the magic of Andrey Arshavin. The Russian was magnificent and played a part in all that was good in Arsene Wenger's side's comprehensive win.
Arsenal got off to the best possible start Nicklas Bendtner's clever turn and through-ball to Theo Walcott left the Blackburn defence flat-footed with barely two minutes on the clock.
Alex Song then pulled the ball back to in the direction of Arshavin for the Russian to reluctantly accept the plaudits as the ball was bundled over the line. Replays showed the ball had actually rebounded into the net off Andre Ooijer.
Arsenal had a good claim for a penalty waived away by referee Phil Dowd as Walcott was blatantly pushed off the ball in the area by Stephen Warnock after 18 minutes.
The referee was also found wanting four minutes later when El-Hadji Diouf should have seen red when flying in with a late dangerous tackle on Manuel Almunia. The Gunners' keeper was lucky not to have suffered a broken leg and the Blackburn man was fortunate to escape with a yellow.
Almunia was called into action in the 27th minute when he tipped over Morten Gamst Pedersen's looping header after Johan Djourou only half cleared.
Samir Nasri went close twice in a matter of seconds in the 36th minute when his free-kick from the left flank had Paul Robinson beaten, but cannoned back off the crossbar.
The ball found its way back into the box, this time from the right flank. Bendtner brought the ball down for Nasri to unleash a snap shot that Robinson palmed away for a corner.
The Gunners should have extended their lead after the interval with both Walcott and Bendtner wasting good opportunities. Within second of the re-start Walcott was away on the right side of the Rovers area, but dragged his shot wide.
Sixty seconds later Walcott was again free on the right flank and the winger squared the ball for Bendtner, who slid in but sent the ball wide from just two yards out.
The Gunners kept the pressure on and Robinson had to make a good save from an athletic overhead kick from Walcott and then Christopher Samba was in the right place to block Denilson's fiercely struck shot.
Bendtner again went close on the hour but his header from Nasri's cross was forced wide under pressure from Samba.
Then two minutes later after a driving run from Kolo Toure who passed to Song, who in turn threaded a delightful ball for the Dane, his tame shot was too easily claimed by Robinson.
The crowd were getting frustrated with Bendtner who missed another opportunity seconds later when he took too long to get his shot off and when he did fired it straight into a Blackburn defender.
The Gunners got the second goal they deserved via a piece of Arshavin magic after 65 minutes. The Russian was found on the left flank by a diagonal ball from Denilson.
He then got to the by-line, skipped past his marker Danny Simpson and then shot into the roof of the net right-footed from the acutest of angles.
Gamst Pedersen forced a save out of Almunia after Arsenal's wall crumbled as the Norwegian fired a free-kick in from 20 yards out that the Gunners keeper saved before the ball completed its route into the bottom right corner of the net.
The Gunners kept going for goals in the knowledge that Blackburn offered little in attack and Emmanuel Eboue was inches away from getting on the end of an Arshavin cross in the 86th minute.
The Ivorian got on the scoresheet a minute later when he fired home from close range after Robinson had only half saved a shot from the rampant Arshavin.
A cool Eboue made it 4-0 in the 90th minute from the penalty spot, after Carlos Vela was hauled down in the box.