The winner of the replay (date still to be announced) will then face Manchester City at Wembley in the semi-final on the weekend of 13/14 April.
On Sunday at Old Trafford, goals from Javier Hernandez and Wayne Rooney put a dominant home side two ahead inside 11 minutes, but a second-half fightback from the visitors spawned goals from Eden Hazard and Ramires and earned the Blues a replay at Stamford Bridge.
Sir Alex Ferguson's side looked to have buried the tie by the interval but were punished for a lacklustre second-half display as Chelsea deservedly fought their way back into the tie. The visitors would have won, too, but for a stunning last-minute save from David De Gea to deny Juan Mata.
The boss made just four changes to the side that exited the Champions League against Real Madrid, with Wayne Rooney, Chicharito, Shinji Kagawa and Jonny Evans returning to the Reds' starting XI.
While the pre-match atmosphere at Old Trafford failed to replicate the unyielding din that soundtracked last Tuesday's tie, it wasn't long before the home support had something to shout about.
There seemed little danger for the visitors when Michael Carrick meandered through central midfield, but without warning the Reds' chief string-puller dug out a magnificent diagonal pass that fell perfectly for Chicharito to loop a marvellous header over the stranded Petr Cech.
Less than five minutes had passed then, and the 10-minute marker bisected the award and conversion of a free-kick that doubled the Reds' lead. A lightning break from the hosts culminated in Victor Moses clumsily halting