Nicolas Jackson was sent off just minutes after his introduction off the bench as Chelsea collapsed in defeat to Flamengo in the Club World Cup.
Pedro Neto fired the Blues ahead early but Enzo Maresca's side conceded twice and saw Jackson dismissed for a horror tackle in the space of six just minutes after the break.
Their woes were compounded when Wallace Yan wrapped up the scoring late on, adding to earlier goals from fellow substitute Bruno Henrique and veteran Danilo.
The result - played out in front of a crowd of 54,019 at Lincoln Financial Field - left Chelsea with a win and a loss from their two outings in Group D having earlier looked set to take a giant stride towards the last 16.
Benfica ran riot in the second half of their Group C clash with Auckland City as they won 6-0.
The Portuguese side were only 1-0 ahead at half-time thanks to Angel Di Maria's penalty.
After a 30-minute delay due to an electrical storm in the area, play resumed and it was Benfica who were electric.
Vangelis Pavlidis scored in the 53rd minute, with Renato Sanches adding another 10 minutes later.
Leandro Barreiro scored two in two minutes to put the New Zealand club to the sword and Di Maria's second penalty of the game deep into stoppage time finished it off.
Group C is likely to be decided by Benfica's clash with Bayern Munich, who play Boca Juniors in the early hours of Saturday morning.
Additional reporting by Press Association.
