Chelsea's woes continued when the holders were dumped out of the Capital One (League) Cup fourth round following a shootout defeat by Stoke City, while Arsenal suffered a humiliating 3-0 defeat at second tier Sheffield Wednesday.
Boss Jose Mourinho will be under mounting pressure after Eden Hazard failed to convert the crucial penalty following another testing encounter for Chelsea, who only forced extra time thanks to a last-minute leveller from Loic Remy.
There was to be no solace for a reasonably strong Chelsea side, whose miserable season dragged on as they could not find a winner against Stoke despite playing against 10 men for all of extra time.
It looked like it was going to be their night when Remy cancelled out Jon Walters's stunning strike from early in the second half and Stoke's Phil Bardsley was sent off for a second booking at the close of normal time.
Yet their killer instinct from last term deserted the Premier League champions again and after some superb penalties, Stoke goalkeeper Jack Butland pulled off a stunning save to palm away Hazard's effort for a 5-4 shootout win.
"Losing 1-0 feeling the situation against an experienced opponent... the team did everything. I tried to help too," Mourinho told reporters after suffering his eighth defeat in 16 games this season.
"We try, we try, we try. When we scored the goal it was no more than we deserved."
The shock of the night came at Hillsborough, a ground where Arsene Wenger has never tasted victory, as Arsenal lost to lower-league opposition by a three-goal margin for the first time since February 1959.
Everton 1-1 Norwich City 1-1 (Everton win 4-3 on penalties)
Hull City 1-1 Leicester City 1-1 (Hull City win 5-4 on penalties)
Sheffield Wednesday 3-0 Arsenal 3-0
Stoke City 1-1 Chelsea (Stoke City win 5-4 on penalties)