Tuchel: I don't know why we lost control | Frank: Eriksen 'unbelievable'

Thomas Tuchel struggled to put his finger on what exactly went wrong for Chelsea during their shock 4-1 defeat at home to Brentford but insisted his side were not distracted by the prospect of Wednesday's Champions League quarter-final tie with Real Madrid.

Antonio Rudiger had put Chelsea ahead at the start of the second half with a stunning long-range strike but a Vitaly Janelt double either side of Christian Eriksen's first Premier League goal since his comeback from a cardiac arrest last summer swung the game in 10 minutes. Yoane Wissa then made it four in the final stages.

It was a scoreline similar to the surprise 5-2 win West Brom pulled off at Stamford Bridge almost exactly a year ago. That match, like this one, was the first after the international break and Tuchel accepted his side may have been mentally drained from playing around the world.

However, he said that did not entirely explain the outcome of the contest.

"It was strange because we were working hard for the first goal and we know how hard it is to create chances against Brentford," he said.

"They defend either very high and man mark or defend very deep in a block of 10 men around the box. You need to be patient, have a fluid rhythm and intelligent and clinical to take little chances to have that first goal and break that block down.

"Once we had [the opener] we stopped defending and gave three goals away in 10 minutes. It was very untypical and killed the game for us.

"I don't know why we gave away a big chance straight after the goal and then the next one and from there we did not defend mature enough. We were not aware of the danger in these moments which is also very strange for us.

"We got punished. They made the most of these 10 minutes, which