Chelsea produced a second-half revival to book a place in the FA Cup fifth round against Middlesbrough, defeating Brentford at Stamford Bridge by four second-half goals.
After a frustrating first half Juan Mata broke the deadlock nine minutes after the break, before Oscar flicked in a second from Branislav Ivanovic's cross.
Frank Lampard then took his Chelsea tally to 199 goals with a perfectly timed volley after Mata's delicate cross and captain John Terry capped the afternoon's work with a back post header as Brentford were blown away in 26 second-half minutes.
Having held firm in the opening half, restricting Chelsea to few chances, Uwe Rosler's side showed little resistance during the second 45 minutes and will rue Fernando Torres' late equaliser at Griffin Park in the first game.
Oscar spurned the best opportunity for the Premier League side in the first half, receiving Mata's toe-poked through ball before striking the outside of Simon Moore's left-hand post.
Marcello Trotta thought he'd handed the visitors a surprise lead after slaloming past Terry, but referee Neil Swarbrick chalked the goal off for an earlier foul.
Brentford were to rue their lack of good fortune within 10 minutes of the second half as Mata captialised on a poor clearance from a Petr Cech goalkick, to drive past Moore from 20 yards.
The lead doubled 14 minutes later as the overlapping Ivanovic crossed for Oscar, whose audacious flick evaded a host of Brentford defenders, as well as goalkeeper Moore, and trickled into the net.
Having earlier put Chelsea in front, Mata soon turned provider, his chipped pass finding Lampard who, in acres of space, side-footed home to go within three of Bobby Tambling's all-time club goalscoring record.
Terry put the icing on the cake with 10 minutes left as he beat Moore to Oscar's hanging left-wing cross to score his first goal since November and put a slightly skewed slant on scoreline which didn't reflect a tight and tense first half.
David Luiz's elbow on Brentford substitute Jake Reeves cast a shadow over the closing stages of the game, an incident which referee Swarbrick punished with only a yellow card.
But while Brentford can now refocus on their promotion attempts in League One, the win hands interim boss Rafa Benitez temporary respite after being knocked out of three cup competitions already this season and falling off the pace in the race for the Premier League title.