Chelsea coach Thomas Tuchel was mystified by his team's concession of three goals in 10 minutes in Saturday's shock 4-1 Premier League thrashing by Brentford which consigned the European champions to their first home defeat in six months.
Tuchel said he was happy with the way the Blues, who had been poor in the opening period, started the second half with defender Antonio Rudiger giving Chelsea the lead with an unstoppable shot from more than 30 yards in the 48th minute.
But Brentford tore their hosts apart with three counter-attacking moves that yielded three goals between the 50th and 60th minutes, two of them by Vitaly Janelt and the other Christian Eriksen's first since signing for the Bees.
"We were in the lead and we were in charge. So I did not see that coming," Tuchel told reporters.
"We stopped defending and give three goals away in 10 minutes which was very untypical and which of course killed the game today for us."
The German said he had been expecting his players to be tired after many of them returned from representing their countries during the international break but that did not explain how they crumbled when 1-0 up.
He also said he thought the game would prove to be a blip and did not represent a bad omen for Chelsea's Champions League quarter-final against Real Madrid at Stamford Bridge on Wednesday.
"After so many wins and so many good results, I refuse to make a drama out of it," Tuchel said.
"We will find out, analyse and then we will digest it because there's no other way. It's hard to take because it's very unusual for us what happened today, and then we will refocus on Monday."