Chelsea have sacked manager Thomas Tuchel on the new owners' 100th day in charge after their third defeat of the season.
The former Borussia Dortmund and Paris St-Germain boss exits after winning three trophies in 20 months.
Owner Todd Boehly has placed Tuchel's coaching staff in temporary charge until a replacement is found.
A club statement said the owners believed it was "the right time" to bring in a new head coach.
BBC Sport understands the decision would have been taken regardless of the 1-0 defeat in Chelsea's Champions League opener at Dinamo Zagreb on Tuesday night.