Olivier Giroud scored his first Chelsea goal and assisted two for Willian as they brushed aside Championship strugglers Hull City to reach the FA Cup quarter-finals.
Willian was fantastic throughout and scored the opener with a curling effort from outside the box.
Pedro scored the second when he slipped the ball under David Marshall after latching onto Cesc Fabregas' excellent halfway line pass.
Willian then scored his second from 25 yards after playing a one-two with Giroud.
The France striker's first goal since his move from Arsenal was a smart finish from close range following debutant Emerson Palmieri's left-wing cross.
Hull improved slightly after the break and David Meyler had a penalty saved by Willy Caballero.
Willian almost wrapped up a first career hat-trick late on, but he hit the post from 20 yards.
Chelsea will discover their last eight opponents on Saturday at 20:00 GMT.