|Venue: Ewood Park
MILLWALL booked an FA Cup semi-final date with Wigan Athletic at Wembley thanks to Danny Shittu's first-half header at Ewood Park.
Shittu powered home Chris Taylor's corner to settle a tense quarter-final replay and seal the Lions' third trip to the national stadium in just four years.
Kenny Jackett named an unchanged starting line up from the goalless draw at The Den on Sunday, although striker Nathan Tyson returned to the substitutes' bench at the expense of Liam Feeney.
Blackburn were forced to make two changes to their side as David Dunn and Martin Olsson came in for David Bentley (knee) and Adam Henley (hamstring) respectively.
Leon Best, making only his second start of the campaign, had the first chance of the evening, drilling low and hard towards goal from the edge of the area but David Forde made a comfortable save.
Millwall launched their first meaningful attack in the eighth minute when Andy Keogh's through ball sent Alan Dunne away down the right wing, but his cross was headed clear for a throw in.
Rob Hulse put the ball in the back of the net after being pulled up for offside in the 13th minute, but replays showed that the QPR loanee had been wrongly penalised by the linesman.
At the other end, Jordan Rhodes blazed over from distance before Best's snap-shot was deflected behind for a corner, from which David Dunn curled narrowly wide.
The Lions then had appeals for a penalty waived away by Premier League referee Mark Clatteburg after Dany N'Guessan's shirt appeared to be tugged by Jason Lowe inside the box.
Taylor saw two carbon-copy efforts from 20-yards out sail wide in the 24th and 29th minute and then, after a handball shout in the 41st minute, the winger's shot was deflected behind.
But Millwall took the lead from the resulting corner when Shittu escaped his marker and powered a downward header into the bottom corner to send the travelling faithful ballistic.
The start of the second period was a cagey affair with little goalmouth action and the home fans inside Ewood Park grew increasingly restless as their side struggled to make simple passes.
There was not an opportunity of note after the break until the 64th minute when Best got goal-side of the defence, drilled a low shot beyond Forde only to see Shane Lowry clear the ball off the line.
Rhodes hammered a shot high and wide before Jackett introduced Jimmy Abdou from the bench at the expense of N'Guessan in a bid to shore up his midfield.
Abdou's introduction had the desired effect as Millwall began to retain possession for long spells. Taylor attempted to score a spectacular second in the 80th minute, but skewed an effort wide.
Blackburn had a flurry of late half-chances but neither Best nor substitute Nuno Gomes could test Forde with efforts from the edge of the area and the Lions held on, despite a late miss by Taylor.