Thomas Tuchel suffered his first defeat as Chelsea manager after a remarkable 5-2 defeat at home to West Bromwich Albion on Saturday.
Tuchel was named Premier League manager of the month on Friday after his record-breaking unbeaten start since replacing Frank Lampard in the Stamford Bridge dugout.
And the German’s superb start looked set to continue when Chelsea took the lead through Christian Pulisic in the 27th-minute. But when Thiago Silva was shown a red card for a second bookable offence, West Brom turned the game on its head during two frantic minutes of first half stoppage time.
First Matheus Pereira levelled when he latched on to a route one ball from goalkeeper Sam Johnstone and lobbed Edouard Mendy, and the Brazilian then doubled his tally with a calm finish.
That set the tone for a frenetic second half as substitute Callum Robinson scored a thumping volley in the 63rd minute, before Mbaye Diagne made it 4-1 to the Baggies five minutes later.
Mason Mount, brought on at half time, pulled one back for Chelsea, but as the Blues pushed forward in search of an unlikely fightback, West Brom scored their fifth when Robinson finished in injury time.