Arsenal went the way of Manchester United at Ewood Park after Morten Gamst Pedersen scored for the eighth time in the Premiership this season to give Rovers the victory that enabled them to leap-frog the Gunners and move into fifth place.
Pedersen struck after 18 minutes but injured himself in the process and had to be substituted 90 seconds later.
The Norwegian's sidefoot finish at the near post finished off a superb move in which Craig Bellamy had skipped past Philippe Senderos before delivering an inch-perfect cross.
Blackburn refused to let Pedersen's early departure spoil their gameplan and the home side could have well had more goals.
Robbie Savage was only just too high in attempting to guide home a fierce cross from Steven Reid.
Andy Todd, outstanding at the heart of the Rovers defence, might have also had a goal, his close-range header also going the wrong side of the crossbar.
Arsenal's early play was bright without a cutting edge and their only attempts at goal came from set-pieces.
Thierry Henry had two free-kick opportunities in the space of 5 minutes, but his first one was charged down by the Blackburn wall and his second was easily held by Brad Friedel.
Arsenal, so triumphant at Real Madrid on Tuesday, were not able to handle Blackburn's competitive edge and it seemed as though their performance in Spain had taken a lot out of them.
That said Senderos was unfortunate to see a header flash wide and, during a spell of Arsenal pressure in the second half, Emmanuel Adebayor had a header well saved by an alert Brad Friedel.