The 25-year-old, will join up with the Blues as soon as he receives his work permit in a deal thought to be for around £31million, although this figure has yet to be disclosed.
Anzhi have agreed to the sale of Willian who they signed from Shakhtar Donetsk in last season's January transfer window, after deciding to list their whole squad at the end of the season.
The Winger made his debut in the Europa League last season against Newcastle and was subsequently injured, and despite only making a further 11 appearances for the Russian club, it seems as though Chelsea have seen enough to commit.
The Brazilian international was initially offered to Tottenham, but when Spurs refused to improve the salary package, his management offered him to other clubs and long-time admirers Chelsea made their move, striking a deal and even completing a medical.
The news broke on the clubs official website this morning when the following message appeared: "Chelsea Football Club can confirm an agreement has been reached with both Willian and his club Anzhi Makhachkala for the transfer of the Brazilian player.
"The transfer is subject to a work permit hearing on Wednesday."
The deal means that Willian will be Chelsea's third summer signing, following the arrivals of Andre Schurrle from Bayer Leverkusen and Marco van Ginkel from Vitesse Arnhem, it is possible that this deal will see the end of rumours surrounding Wayne Rooney who is set to face the Blues when Manchester United meet them tomorrow night.
The news of the new signing will mean that Manchester United manager, David Moyes may rest easier in the knowledge that one of his best players can now concentrate on a campaign with the champions.
image: © Jason Bagley