Leicester City manager Claudio Ranieri said there were two key moments that saw his side slump to defeat in Tuesday's 4-2 EFL Cup defeat to Chelsea.
The Foxes surged into a two-goal lead thanks to Shinji Okazaki's first-half brace.
But a Gary Cahill equaliser with the last kick of the first half changed the moment of the game, and the defending Premier League champions were given a mountain to climb going into extra time thanks to the 89th-minute sending off of centre-back Marcin Wasilewski.
"There are two keys for this match," Ranieri told Sky Sports after the game. "The first was when we conceded a goal at the end of the first half and the second key was when Wasilewski was sent off.
"At that point it was very hard against a team with high quality. They moved the ball very quick, very fast and then it was difficult for us."
A quick-fire Cesc Fabregas double in stoppage time sealed the win for the visitors, ending Leicester's chances of adding the EFL Cup trophy to their expanded trophy cabinet.
The Foxes will return to Premier League action against Manchester United on Saturday, while Chelsea face London rivals Arsenal.