England manager Gareth Southgate admitted his side still have a long way to go to become a "top team" after their first qualifying loss in 10 years on Friday as the Czech Republic came from behind to win 2-1 in Prague, reports AFP.
The Three Lions could have secured their place at Euro 2020 with victory and got off to a great start through Harry Kane's early penalty.
However, Jakub Brabec quickly levelled for the impressive Czechs and substitute Zdenek Ondrasek struck the winner five minutes from time to inflict England's first qualifying defeat in 44 games since a 1-0 loss to Ukraine in 2009.
"Clearly that's a night we did not want to be a part of. We didn't play well enough, it's as simple as that," said Southgate.
"We've always maintained there is a lot of work to be done to be a really top team. Tonight was clear evidence of that."
England still top the group thanks to their better head-to-head record with the Czechs on 12 points, but now have work to do in their final three qualifiers, starting with a visit to Bulgaria on Monday.
"To sail through a qualifying group with no issues is unusual so we have to respond and I expect us to do that," added Southgate.
"Football is all about responding to setbacks. We haven't had too many so it feels even more unpleasant. None of us like it, but that's the reality."
England had plundered 19 goals in their first four qualifiers, including a 5-0 thrashing of the Czechs back in March, and another comfortable evening seemed in store when the visitors went in front after just five minutes.
Raheem Sterling sped in behind the Czech defence and as the Manchester City forward cut inside, he was brought down by Lukas Masopust.
From the resulting penalty, Kane confidently slotted home for his 27th international goal.
However, rather than going onto showcase why they will be among the favourites to win Euro 2020 with an abundance of attacking talent and home advantage on their side for most of the tournament, England showed the defensive frailties that could easily cost them next summer.