Ten man Liverpool stuck to their tasks and gained a well deserved three points thanks to an Andy Carroll injury time winner.
The reds made 6 changes to the team that drew against Aston Villa at the weekend. Amongst the players rested were Gerrard and Suarez. Gerrard's loss on paper wasn't too significant - he has started 11 games in the Premier League this season for Liverpool - ending up on the winning side only once.
Glen Johnson also came back in to the Liverpool side, with Andy Carroll returning to the starting line up. Maxi and Bellamy also got the nod ahead of Downing and Kuyt.
Liverpool controlled the early play, although Jon Flanagan found himself caught in possession and looked nervy.
In the 13th minute however the reds opened the scoring. Skrtel's cleared pass magnificently found Bellamy, who's low cross found Maxi Rodriguez - alert and available in the box.
Three minutes later and the reds were 2-0 up. Shelvey's fine work, and then a rebound from a Carroll attempt allowed Rodriguez to get his name on the scoresheet again.
Maxi may only be able to run around for 45 minutes - but he certainly could show Stewart Downing a thing or two about finding the penalty box.
So Liverpool are a quarter of an hour in to the game and cruising.
In the 25th minute, Liverpool's FA Cup Semi Final plans are thrown in to chaos when Jon Flanagan, already in the referee's book for a poor tackle, plays a terrible backpass straight to Junior Hoilett. Doni has little choice but to try and close down the angle, and Hoilett tumbles over Doni's body block.
Doni sees a red card, and three match ban, and Blackburn are awarded a penalty.
Brad Jones, the reds third choice keeper, and now the keeper for the semi final, is subbed on to replace Flanagan. First job is to face Yakubu's penalty. His former teammate at Middlesbrough steps up - and with his first touch of the ball in the Premier League - Brad Jones saves the tame penalty.
Blackburn did apply some pressure against the 10 man reds, and after Bellamy handled outside the area, Yakubu scored a header from the resultant free kick, as the reds maintained their 2-1 lead at half time.
On the hour mark though Blackburn drew level. A backpass to Jones placed him under pressure - his clearance was charged down by Yakubu - he palmed the rebound away before a penalty was awarded for him pushing Yakubu.
This time Yakubu put the penalty away to place the game level at 2-2.
Both teams applied pressure on the winner - Jonjo Shelvey chasing down the Blackburn defence to create himself a chance, moments before Andy Carroll's diving header went narrowly wide.
As the game entered injury time, and with Agger now on the pitch, the Dane's knockdown was met with Andy Carroll's head to secure the Liverpool winner and wild celebrations from the 6,000 strong travelling Kop.
Doni's red card has created a new FA Cup Semi Final problem for Liverpool, but managing to pull off the victory when a man down will be a big confidence boost for the reds.
Liverpool head to Wembley in pursuit of their second trophy of the season.