Chelsea lost their perfect record in this season's Premier League after an entertaining 2-2 draw at Swansea on Sunday.
Diego Costa scored both goals for Chelsea, including the equalizer, but the result left them second, two points behind Manchester City, who have 12 points out of 12.
"It's a bit difficult to talk about the game, because we lost two points," Chelsea manager Antonio Conte said.
"We were dominating the game and leading 1-0 and created a lot of chances to score the second and third goals. It's a pity because when you have the possibility to kill the game you must kill the game."
"We have to learn that after this game. Tomorrow we start to work again and prepare for the Liverpool game (on Friday)."
Costa's goal, after a Swansea mistake, put Chelsea in front and they were dominant until half-time.
But Gylfi Sigurdsson equalized from the penalty spot on the hour mark after he was fouled by Thibaut Courtois, and Leroy Fer put Swansea in front three minutes later, though defender Garry Cahill was convinced he had been fouled.
"Come on, seriously! You could be sat on the moon and see it is a clear foul," he said.
"I took the touch away from him, he came through the back of me. It was clear as day and seeing it back has made me even more angry.
"It's all fun and games for the fans isn't it but it's the players who suffer. That kills me and kills my team. We have dropped two points which is massive in this league."
Costa, who was involved in a number of controversial moments during the match, equalized with a brilliant bicycle click nine minutes from time.
Both sides chased a winner in the remaining minutes, but Lukasz Fabianski denied Costa a hat-trick to give Swansea a share of the points.
The point lifted Swansea up to 13th, two points clear of the bottom three.
Swansea manager Francesco Guidolin has still never won a match against a side managed by Conte but said he was pleased with the result.
"My team played the second half with more energy against a very strong team," he said.
"Chelsea didn't deserve to lose this game but we had a good reaction in the second half and after 90 minutes of fight it is a good result."