Chelsea struggled to get the lead as home side Wolverhampton Wanderers showed a great performance in the first half with goal attempts and several chances created.
At 6′ former Chelsea youngster Saville struck the post as Kurt Zouma did not control a high ball into the penalty area.
Willian went close to scoring a few minutes later with a lob, well scrambled away by Wolves keeper Ikeme.
In the second half Diego Costra tried to score first: the Spaniard twisted but his shot crashed into the side netting.
Chelsea unmarked winger Pedro found a crucial goal at 65′ taking advantage of a wonderful ball from Willian. Then Diego Costa didn’t waste his second chance and scored with a low clinical shot after receiving the ball from Fabregas.
Chelsea win a tough game, which means that Antonio Conte goes through next stage reaching FA Cup Quarter-Finals.
Wolves were a difficult obstacle today but the Blues are into Sunday evening's FA Cup quarter-final draw. #WOLvCHE
— Chelsea FC (@ChelseaFC) February 18, 2017
Chelsea (3-4-3): Begovic; Zouma, Terry (c), Ake; Moses, Fabregas, Chalobah, Pedro (Azpilicueta72); Willian (Kante 80), Diego Costa, Hazard (Loftus-Cheek 85).
Unused subs: Eduardo, Cahill, Kenedy, Batshuayi.
Scorers Pedro 64, Diego Costa 89
Booked Pedro 48
Wolverhampton Wanderers (4-2-3-1): Ikeme; Coady, Batth (c), Hause, Doherty; Price, Saville (Saiss 83); Costa, Edwards, Weimann (Wilson 74); Bodvarsson (Ronan 83).
Unused subs: Burgoyne, Stearman, Evans, Saiss, Rona, Enobakhare
Booked Saville 20, Weimann 32
Referee Jonathan Moss