The home side were ahead in the fifth minute, Fernando Torres beating Paul Robinson with a stunning first-time right-footed volley from Jamie Carragher's ball over the top. Rovers were rocked and Liverpool went on to dominate possession with Dirk Kuyt missing a couple of good chances.
Torres grabbed his second in the 34th minute, heading Xabi Alonso's free-kick past Robinson. Blackburn, with Christopher Samba playing up front, were not able to really threaten Jose Reina's goal in a one-sided first half.
Liverpool didn't show the same cutting edge in the early stages of the second half and Samba almost pulled one back for Rovers but Reina was able to make the save.
The points were sealed however in the last 10 minutes, Daniel Agger making it 3-0 in the 83rd minute with a 30-yard drive which flew into the top right-hand corner. Substitute David N'Gog got the fourth in the last minute, nodding the ball over the line from Yossi Benayoun's header back.
Liverpool regain the top spot in the table, for a couple of hours at least, while Rovers are still nervously looking over their shoulders.