Liverpool went ahead midway through the first half when they scored from a free kick in front of Chelsea keeper Carlo Cudicini's right-hand post.
John Arne Riise tapped the free kick to Steven Gerrard who stopped the ball dead for the Norwegian left back to curl a low shot between Paulo Ferreira and Frank Lampard at the near end of the wall and past the unsighted Cudicini.
Chelsea conceded the second goal from a throw-in on the right when a poor headed clearance fell to Luis Garcia and the Spaniard raced goalwards with three defenders in his wake to hit a dipping shot high into the far top corner.
Striker Didier Drogba headed Chelsea back into the game with 20 minutes to go. Riise made a poor effort of clearing the ball with a diving header and keeper Jose Reina raced off his line to try to foil the striker but was just beaten to the ball.
Middlesbrough and West Ham United meet in the other semi-final at Villa Park in Birmingham on Sunday.
