Thomas Tuchel has admitted that his Chelsea players were “sloppy” as they “got punished” by Brentford on Saturday afternoon.
The Blues went ahead at the start of the second half as Antonio Rudiger scored from distance.
Vitaly Janelt struck back for Brentford moments later before Christian Eriksen made it 2-1 in the 54th minute.
Janelt added his second and Yoane Wissa scored before the end as the Bees ran out 4-1 winners at Stamford Bridge.
This defeat ends Chelsea’s six-game winning run across all competitions. Fourth-placed Arsenal will close in to within two points of the Blues if they beat Crystal Palace on Monday night.
Tuchel said after the loss that his players simply “stopped defending” in the second half:
“Nobody saw it coming, especially after going 1-0 ahead. It was very untypical of us. But we stopped defending. We were not aware enough of the danger, were sloppy with the defending and got punished,” Tuchel told BBC Sport.
“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.
“The start was not a surprise because we came from all over the world from national duty so I expected it to take time. For the first 25 minutes we looked a bit leggy and needed to find the rhythm.
“The opponent defended deep with 10 men behind the ball so you need a shot or action to open the game, which we did. Then we gave the game away very cheaply.”
On how this affects preparations for Real Madrid in midweek: “It is not about Real Madrid. It is about us. It is one day off now and on Monday we start again.”
Brentford defender Rico Henry said post-match that Eriksen “is on fire at the moment”:
“We had a lot of legs and we worked hard for one another.
“Christian Eriksen is quality on the ball and has been excellent since he has been in our changing room. He is on fire at the moment and long may it continue.
“It’s a big win for us. It’s a good day for us.”