A third sending off in five games prevented Mikel Arteta's side from earning maximum points against Southampton, extending the Gunners' winless league run to six matches.
Man City's 2020 haze continued in a 1-1 draw with West Brom, City again lacking the sharpness, ruthlessness, and goals of a typical Pep Guardiola side.
Kai Havertz and Timo Werner arrived to much fanfare, but the German internationals struggled again at Wolves, where Chelsea suffered their second straight Premier League defeat.