Joao Felix was sent off on his Chelsea debut for a studs-up tackle as the Blues lost 2-1 at Fulham in the Premier League to fall deeper into crisis on Thursday.
The Portugal forward looked disconsolate after being shown a straight red card in the 58th minute for his dangerous challenge on Kenny Tete that caught the Fulham right back just below his right knee.
Felix, who joined on loan from Atletico Madrid on Wednesday, was having an impressive game until his sending-off, making surging runs, delivering incisive passes and showing some clever tricks.
But he will now be suspended and miss the league games against Crystal Palace, Liverpool and Fulham, adding to manager Graham Potter's considerable problems after a seventh loss in the last 10 matches in all competitions.
Potter admitted the red card was a turning point. “I thought we started quite well and had a good chance early. I thought we had decent control of the game," he said.
“A couple of mistakes led to their goal but I thought we responded well second half. Then the red card obviously changed the game, making it more difficult for us.
“I thought the application when we were down to 10 was really good but I was disappointed with the goal. We can do better than that.
“That’s what cost us. We’re really disappointed to lose.”
Fulham went ahead in the 25th minute through a deflected shot from former Chelsea winger Willian, only to concede an equaliser in the 47th when Mason Mount’s free kick came back off the post and Kalidou Koulibaly forced home the rebound from close range.
Carlos Vinicius, replacing suspended striker Aleksandar Mitrovic, scored the winner in the 73rd minute, meeting a cross from Andreas Pereira with an unchallenged header at the far post.
Goalscorer Willian told BT Sport: “We deserved the win. We know how difficult it is to play against Chelsea. They are in a difficult moment but we are a really good team. We deserved it and we have to carry on.
“I had an amazing seven years at Chelsea. I have a big respect for the fans and the club. I play for Fulham now and have to do my best. It was a special night.”
The victory lifted Fulham above Liverpool into sixth place to continue a brilliant first season back in the top flight, while Chelsea remain in 10th place and 19 points off leaders Arsenal having played one game more.