Chelsea will travel to Paris on Monday for their Champions League last-16 first leg with confidence restored by interim boss Guus Hiddink and an emphatic defeat of Newcastle, according to Willian.
The Blues' Premier League title defence has been one of the worst in recent history, but Hiddink has restored stability and Chelsea are unbeaten in 12 games since Jose Mourinho was sacked on Dec. 17.
A Pedro double, plus goals for Diego Costa, Willian and Bertrand Traore earned a 5-1 win over the Magpies on Saturday, the only blot on the performance a hamstring injury for John Terry.
"We killed them in 20 minutes and then it was more and more easy to play,'' Willian told Chelsea TV. "Now we have more confidence to go there and to play. Paris have a great team, great players, but we go there to try to win the game.''
Willian and Costa, who played in a protective face mask after breaking his nose in training on Thursday, revelled in the miserable Magpies defending to lead the destruction of Chelsea's visitors.
Costa struck his eighth goal in 10 matches -- seven in eight Premier League games -- to begin the rout.
"Diego is a great player. We have no doubts about him, about his quality. He's scored so many goals," Willian added. "I gave one assist for him, he gave one to me. I enjoy a lot playing with him.''