Two second-half goals were enough to see Chelsea into the fourth round of the Carling Cup at Blackburn's expense.
Joe Cole celebrated his first start of the season by converting Salomon Kalou's cross after 53 minutes.
Kalou tapped in the second after Brad Friedel had parried substitute Shaun Wright-Phillips' shot.
Blackburn had their chances in an entertaining tie, with Shabani Nonda looking particularly lively, but Chelsea were too strong.
Rovers boss Mark Hughes, in his 100th game in charge, also saw Nonda and Morten Gamst Pedersen pick up injuries.
It was Nonda who had the first chance of the game, the striker bursting through before sending his effort narrowly wide.
But Chelsea got into their stride, with the lively Kalou and Arjen Robben going close.
Blackburn almost took the lead in the 41st minute when Pedersen rattled in a free kick from distance but Hilario turned the ball around the post and it was scoreless at half-time.
Pedersen limped off in the 48th minute and Rovers' plight worsened five minutes later when Cole put Chelsea ahead - although the hosts were convinced the England midfielder had handled the ball in the lead-up to the goal.
Nonda was then stretchered off after a collision with John Terry, who later had a header scrambled away.
A minute after coming on, Wright-Phillips delivered the killer blow to Blackburn's hopes of recovery.
Brad Friedel did well to parry the winger's fierce effort in the wet conditions but Kalou raced in to fire home the rebound.