With the rain pouring down and a slightly under-strength Chelsea only back from a draining trip to Japan on Monday, conditions had been ripe for an upset in what has been a season of surprises in the competition.
"The reaction in the second half was fantastic, especially with travelling back from Japan and having jet lag," Chelsea interim coach Rafa Benitez said. "We were looking for character and the reaction was so good."
Leeds would have loved nothing more than to get one over a team that has been one of its big rivals since the mid-1960s and '70s, when they were arguably the two leading clubs in England.
Police were on high alert for trouble but the match appeared to pass off without major incident off the pitch, although there were some strong tackles on it in the early stages. Lampard was booked for one particularly tough challenge on former Senegal forward El-Hadji Diouf, one of the most volatile players in English football.
An upset was on the cards when Becchio slotted home a low cross by Jerome Thomas eight minutes before the break, the most incisive moment of a hard-fought first half.
Yet, Chelsea soon displayed a ruthless side that was sorely lacking against Corinthians, having 10 shots on target in the second half and scoring from five of them.
Mata jolted Leeds by squeezing in a shot from the edge of the area, with goalkeeper Jamie Ashdown perhaps at fault.
Then the floodgates opened, with substitute Eden Hazard helping Chelsea run amok.
Ivanovic headed in Lampard's left-wing corner to the near post in the 64th and Victor Moses drilled in a shot from 20 yards two minutes later.
Eden Hazard run onto a fine through-ball from marauding center back David Luiz for the fourth in the 81st and Torres finished off Leeds, tapping in from Hazard's cross.
"They took over and we could not cope," Leeds manager Neil Warnock said.
-AP