The 50 million-pound ($79 million) Spanish striker scuffed a shot into the net after 67 minutes to send the crowd into raptures and struck again with a deft late header as Chelsea's revival continued under caretaker manager Roberto Di Matteo.
"I needed those goals, in the last month the team is much better than before," man-of-the-match Torres told ESPN. "I have been playing well but not scoring goals. We are creating more chances than before and we are much better defensively." Defender Gary Cahill headed Chelsea's first goal before revealing a t-shirt with "Pray for Muamba" written on it, a reference to his former Bolton Wanderers team mate Fabrice Muamba who collapsed during the FA Cup tie against Tottenham Hotspur on Saturday and remains critically ill in hospital.
Torres set up the second for Salomon Kalou to put Chelsea firmly in control and the Spaniard's first goal in 25 matches effectively sent the London club into the last four before the match ended in a flurry of action.
Leicester pulled one back through Jermaine Beckford, Torres neatly glanced in a corner, Ben Marshall's superb 25-meter shot flew past Chelsea goalkeeper Petr Cech and Torres set up his side's fifth for Raul Meireles in stoppage time.
"He (Torres) had a terrific game, he worked so hard for the team and it was a wonderful day for him," Di Matteo said. "I always had a lot of belief in him and I thought it would just be a matter of time." Liverpool host Stoke City in the last quarter-final later on Sunday.
Everton drew 1-1 with Sunderland on Saturday and the game between Tottenham and Bolton was abandoned before halftime with the score at 1-1 after Muamba collapsed on the pitch.
