Romelu Lukaku enjoyed an impressive second debut for Chelsea, as he helped the Champions League winners to a 2-0 win at Arsenal on Sunday.
The 28-year-old returned to the Stamford Bridge this week and was pushed into the starting XI at the Emirates by Thomas Tuchel.
The £98 million record signing opened scoring within 15 minutes, tapping Reece James' cross from the right into an empty net.
James himself doubled Chelsea's lead before the break, firing high into the net past Bernd Leno.
The Gunners tried to fight their way back into the game, but Mikel Arteta's men barely threatened their London rivals, as they suffered their second consecutive defeat this season.
Meanwhile, Tuchel's men have climbed to the top of the summit, ahead of next week's trip to Liverpool.