Chelsea manager Rafael Benitez said he was left perplexed by his team's failure to beat relegation-threatened Reading at the Madejski Stadium.
The Blues squandered a two-goal lead late on as Royals substitute Adam Le Fondre's goals salvaged a 2-2 draw.
"It's difficult to explain how we drew this game," said Benitez.
"We did everything to win the game. For 85 minutes we controlled everything and created enough chances to score four or five goals. It is difficult to take."
Third-placed Chelsea looked set to clinch their fifth successive top-flight away win after goals from Juan Mata and Frank Lampard put them firmly in control.
But they switched off twice in the closing stages as Reading claimed a point that means they climb out of the relegation zone.
Le Fondre was unmarked as he slid Hope Akpan's through-ball past stand-in Blues goalkeeper Ross Turnbull at his near post, before the visiting defence failed to deal with a long punt into their penalty area which was headed down for the Royals striker to level.
Victory would have cut the gap between the Blues and second-placed Manchester City to four points.
"We all take responsibility. We don't blame anyone. It's for us to analyse why we didn't kill the game off, and to work to stop the mistakes," added the Spaniard.
"We're still in a really good position in the table, but it could have been better.
"We are improving a lot. We did an exercise with corners and free-kicks on Tuesday and it was fine. Today for 85 minutes it was perfect."
Reading boss Brian McDermott praised Le Fondre's goalscoring instincts after the 26-year-old stepped off the bench for the third successive Premier League match to earn precious points in his side's battle against relegation.
He scored the Royals' equaliser in a 3-2 comeback win against West Bromwich Albion, before adding two more to clinch a 2-1 win at Newcastle.
"If you have got Adam Le Fondre at your club you have always got a chance," said McDermott.