Antonio Conte conceded Chelsea are out of the title race after their 1-0 defeat at West Ham.
Marko Arnautovic's early goal condemned the Blues to a fourth defeat of the season and left them 11 points adrift of leaders Manchester City.
Chelsea have been pushed out from 22/1 to 33/1 in Sky Bet's title odds.
Conte admitted: "This is the fourth defeat in 16 games. When you have these stats it's impossible to think you are in the title race.
"If you want to stay in the race for the title in the first part of the season you can only lose once or twice."
Chelsea defender Gary Cahill was blunt in his assessment of his side's performance.
"We were not at the races today, whatever the reason, it is very disappointing," he said. "If we play to our levels we get something out of the game, but we didn't so we didn't."
David Moyes admitted his relief at getting his first win as West Ham boss.
"The win was the biggest thing, to get a win in the Premier League is really hard especially against the champions," the Scot said to Sky Sports.
"The spirit of the team, how they stuck together pleased me. The basics were in the main done well.
"I got a big boost from the performance at Manchester City, we didn't take any points from it, but there was something to talk positive about.
"We look harder to beat at the moment, we have people who can create and score goals so if we can get the back end sorted we might give ourselves a chance of earning some points."
