Last season's FA Cup runners-up Chelsea struck four times before the break to crush second-tier Hull City 4-0 and stroll into the quarter-finals at Stamford Bridge on Friday, while Leicester City also reached the last eight after a 1-0 win over Sheffield United.
Willian bagged two and Olivier Giroud scored his first goal for the club since joining from London rivals Arsenal, while Pedro was also on target for Antonio Conte's dominant side.
Republic of Ireland international David Meyler had a 51st-minute penalty saved by Willy Caballero as the visitors were denied a consolation goal in the second half.
However, prior to the spot kick, Willian appeared to distract Meyler with a cheeky comment just before the Corkman missed.
Meyler turned around and ruffled Willian's hair - with both men all smiles
The night's other fifth round tie saw Leicester City also in action against Championship opposition but having to work far harder for their victory over the Blades.
Jamie Vardy struck the only goal after 66 minutes, the fifth game in a row in all competitions he has been on target.
Leicester held on to reach the quarter-finals for the first time since 2012 when they were knocked out by eventual winners Chelsea -- the last time the west London club won the Cup.