Second-half goals from Willian, Loic Remy and Kurt Zouma sent Chelsea through to the FA Cup fourth round with a 3-0 win over Watford at Stamford Bridge.

The Premier League leaders were held by their London rivals until half time, but turned it on after the break with a spell of three goals in 14 minutes.

After a Christmas without much rotation, Jose Mourinho rested key men such as Eden Hazard, Nemanja Matic and Cesc Fabregas for visit of the Championship promotion hopefuls.

Didier Drogba captained the second-string Blues and had their best chance to open the scoring when his thumping header was well kept out by Jonathan Bond.

World Cup winner Andre Schurrle has found opportunities hard to come by of late for the Premier League leaders and will not have impressed Mourinho by blazing over when well placed on 24 minutes.

Defender Gary Cahill proved a constant threat from dead-ball situations and glanced a near-post header just wide. Set pieces appeared the most likely source as Chelsea struggled to unlock the Hornets.

The visitors, who are managed by former Blues flop Slavisa Jokanovic, had a couple of half-chances themselves as Troy Deeney and Daniel Tozser brought comfortable saves out of the recalled Petr Cech.

For his second match in succession, Schurrle was hooked at half time and his replacement Willian fired Chelsea into the lead on 58 minutes with a bending shot from 25 yards which found the top corner.

Watford had previously come close to going ahead when Deeney's shot took a deflection off Filipe Luis and narrowly missed the bottom corner, but they were soon facing an unassailable three-goal deficit.

Remy doubled Chelsea's advantage on 70 minutes with a smart half-volley which continued his record of scoring in every start for the club, and Zouma put the result beyond doubt with a powerful header from Cesar Azpilicueta's cross two minutes later.