Over at Boundary Park, Everton were caught by a Matt Smith equaliser in the 94th minute - in truth nothing more than Oldham deserved after another battling display. They previously beat Liverpool in the fourth round and the financial rewards will be vital for Oldham as they battle against relegation from League 1.
They now have a replay at Goodison Park in 10 days time.
Arsenal are the latest in a long line of top flight clubs that have bit the dust this season and Blackburn won thanks to a second half goal from Colin Kazim-Richards.
Arsene Wenger's side will rue missed opportunities throughout the match but having rested key players Wenger may think wice in the future of doing so. They don't seem to have the strength in depth of old.
As a result, Kazim-Richards' effort proved decisive as his shot went in off the post to send Blackburn into the quarter finals.
Elsewhere, the form book went to script as Luton's hopes of becoming the first non-league club to reach the FA Cup quarter finals in 99 years were dashed by Millwall. Despite their home advantage, the Blue Square Premier side were beaten 3-0 at Kenilworth Road.
Two of Millwall's goals came in the first half from James Henry and Rob Hulse, with Dany N'Guessan adding a late third.
Millwall manager Kenny Jackett said: "It's a great result for us. We knew it was going to be a really difficult game and we're delighted to be in the last eight. We're one game away from Wembley now so we'll take anyone."
Chris Dagnall scored twice for Barnsley as they beat MK Dons 3-1.
The 26-year-old had opened the scoring after just three minutes, before Marlon Harewood doubled their lead midway through the first half.
The Dons pulled one back through Dean Bowditch after the break, before Dagnall scored again to put the result beyond doubt.
So far no Premier League sides are into Round 6!