Chelsea manager Jose Mourinho said his side's Premier League title chances were over after a lacklustre display in their 1-0 defeat at Crystal Palace.
The Blues are still top but are only a point clear of Liverpool and two ahead of Manchester City, who have played two matches fewer and drew 1-1 at Arsenal.
Asked whether Chelsea could still win the league for the first time since 2009-10, Mourinho said: "Now it's impossible to win the title.
"We depend too much on other results."
He added: "When you depend a little it's possible, when you depend a lot I don't think it is possible.
"Mathematically it is still possible but one thing is mathematics and another is reality."
Palace, whose victory was their first in six games, went ahead when Chelsea captain John Terry headed Joel Ward's cross into his own net.
Mourinho admitted his side deserved nothing against a Palace team who are still only five points clear of the relegation zone despite a hugely impressive win.
He praised defenders Branislav Ivanovic, Cesar Azpilicueta, Terry and Gary Cahill but said the other players lacked the correct "mentality and a little bit of quality".
"Mentality because the opponent beat us clearly on that," said Mourinho.
"Crystal Palace had a strong mentality, were aggressive and committed, with every one of them playing to the top of their potential.
"Ivanovic, Azpilicueta, Cahill, Terry - they perform in the sun, on small pitches, on big pitches, against aggressive teams, not aggressive teams, possession teams and not possession teams. They perform every game from day one to last day.
"But you have other players who are fantastic in some games and they disappear in others."
Mourinho also explained why he ran to a ball boy in injury time after the youngster failed to release the ball to Azpilicueta promptly.
"It is not right to educate kids to do that," said Mourinho.
"I went to stop [Azpilicueta]. I was afraid he would lose control of his emotions and push the kid or do something like Eden [Hazard] did last year at Swansea.
"I told the boy to not do that. I told him if he does this, 'one day somebody will punch you'."
Hazard was sent off in a League Cup game at Swansea last season when he tried to kick a ball away from underneath a ball boy who had fallen on top of it.