Head coach Thomas Tuchel has claimed that his Chelsea side showed complacency during their 4-1 defeat at home to Brentford on Saturday afternoon.
Despite edging in front at the start of the second half, Chelsea found themselves 3-1 adrift by the hour mark after the visitors netted three times in 10 minutes.
Although Chelsea had their moments during the closing half-an-hour, the Bees were deserved winners, leaving their hosts with plenty of work ahead if they want to make sure of a top-four finish in the Premier League.
Speaking to BBC Sport, Tuchel said: "Nobody saw it coming, especially after going 1-0 ahead. It was very untypical of us. But we stopped defending. We were not aware of enough of the danger, were sloppy with the defending and got punished.
"They made the most of it in those 10 minutes. Right after their third goal we had 10 minutes where we had big, big chances and we missed them. They were lucky and clinical enough to get three goals. We did not defend like it is needed to in the Premier League and got punished."
Chelsea remain eight points clear of fifth-placed Tottenham Hotspur, who play host to Newcastle United on Sunday.
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