Gary Cahill and Salomon Kalou gave the Blues a half-time lead before Torres netted either side of a Jermaine Beckford strike.

A late wonder goal from Ben Marshall and a Raul Meireles strike gave the game an impressive scoreline.

Roberto Di Matteo made seven changes to his Chelsea side after their extra-time victory over Napoli in the Champions League. Petr Cech, Branislav Ivanovic, Daniel Sturridge and Juan Mata were retained with Torres starting up front.

Leicester made just one change to their line-up from the Championship game against Birmingham in mid-week, Paul Konchesky returning at left back after a suspension.

The Foxes made a positive start to the game, Beckford finding space on the edge of the box and curling an effort just wide of the far post.

Chelsea took the lead, however, as Cahill rose highest from a Mata corner to power a header in, and the former Bolton man revealed a shirt as he celebrated with a message dedicated to former team-mate Fabrice Muamba as the midfielder continues to recover after collapsing at White Hart Lane on Saturday.

The home side continued to press forward, Daniel Sturridge twisting and turning his way towards goal before feeding Mata who saw a bundled effort hacked off the line by Konchesky.

And the pressure told as the Blues launched up the field on the counter attack, Torres taking the ball down the right flank before squaring to Kalou who took a touch before calmly slotting past Kasper Schmeichel in the Foxes' goal.

Sturridge was looking lively, magnificently trapping a high ball before dinking an effort just wide, with Torres disappointed that he wasn't provided a chance to end his day-long goal drought.

The Spaniard seemed in fine form, planting a header at Schmeichel before the Dane magnificently tipped Torres' fierce 20-yard effort away.

The Championship side kept their heads up and Neil Danns forced Petr Cech to make a good save with a driven shot before Paul Gallagher's long-range effort was deflected away by Cahill.

The former Blackburn winger was then substituted after failing to shake off a knee injury and replaced by Lee Peltier as the half meandered to a close, the home fans giving their team a rapturous reception on the half-time whistle.

The Blues made a change of their own at the start of the second period, Mata given a rest ahead of Wednesday's clash with Manchester City, Florent Malouda his replacement.

The Frenchman stretched Schmeichel with an effort from distance before Sturridge again showed a frustrating lack of teamwork, opting to shoot from an angle with others better placed, in an otherwise quiet opening to the half.

Leicester's travelling fans had been in superb voice throughout the match and were almost rewarded for their support as Lloyd Dyer struck wide after a surging run.

The Premier League side's quality came through, however, Kalou set off down the right before cutting the ball to Torres who swept home a goal for the first time in nearly 26 hours of football as the home crowd erupted in celebration.

The Spaniard then rifled an effort over just moments later before Sturridge stretched to meet a cross from Ryan Bertrand but saw his header drift wide.

The Foxes had continued to push forward and finally got a goal, Neil Danns hit the post from 25 yards and the ball rebounded to Beckford who was on hand to tuck in from close range.

As the away support sensed an unlikely comeback, the Blues regained their three-goal cushion thanks to Torres who did manage a second, bursting ahead of Sol Bamba to nod in a Meireles corner.

Marshall had been brought on as a late sub and scored the game's best goal, picking up the ball in midfield and unleashing a thunderbolt from 35 yards.

The late goals kept coming as Torres turned provider to Meireles, squaring when well placed to shoot for the Portuguese midfielder to slam home.

The win sees Chelsea through to the semi-finals where they will be making their 10th trip to the new Wembley since its 2007 reopening.