The 29-year-old gave his side the lead against their city neighbours to bring his tally up to 13 in all competitions
He may not be a certain starter for Chelsea, but Willian is doing all he can to establish himself as a star for Antonio Conte's side.
The attacking midfielder is outdoing himself amid his team's poor defence of their Premier League title and made this season a personal best against Crystal Palace on Saturday.
The Brazilian opened the scoring for the Blues 25 minutes into the game at Stamford Bridge as he cut inside from the left and sent it in off the post before a Martin Kelly own goal doubled the lead.