England captain Harry Kane has admitted losing to Czech Republic will be a "wake-up" call to the players following their first qualifying defeat in 10 years.
Kane scored from the spot early on when Raheem Sterling was tripped in the penalty area to score his seventh goal of the Euro 2020 qualifying campaign.
But the Czechs fought back immediately with a strike from Jakub Brabec and debutant Zdenek Ondrasek stunned the visitors with an 85th-minute winner.
It was the first time England had been beaten in a qualifier since the 1-0 defeat against Ukraine in October 2009 - a run that stretched for 43 games - and Kane admitted the players were to blame for a below-par performance.
"I think it was down to us," he told ITV Sport.
"It was a perfect start to an away game. We were sloppy with the ball, we didn't move it as quickly and we weren't pressing as we normally do.
"The second half was better, we had a couple of chances to put the game to bed and we didn't and unfortunately we gave one away at the end.
"Every away game in Europe is difficult. They had the crowd behind them, sometimes the pitch is not as easy to play, but that's no excuse. It's a bit of a wake-up call but we're in a good position.
"There's still stuff to work on for sure. We gave the ball away too cheaply and we'll have to go away and look at it. There's no need to panic and we'll go again on Monday."
England would have qualified with three points in Prague but now face a challenge to top Group A after the hosts joined them on 12 points - albeit having played one game more.
Having watched his side throw away an early lead, manager Gareth Southgate said in no uncertain terms his side did not live up to his expectations.
"We've had a lot of credit over the years but tonight we didn't do enough," he said.
"The performance wasn't good enough. We should've got a draw probably, but the goal we conceded was typical of the chances we gave away throughout the night.
"There are things we can look back on, but collectively there wasn't enough good individual performances tonight.
"We tried to change shape in first half which wasn't working and I think we looked more of a threat in the second and had enough good chances to win in truth."
The Three Lions travel to Sofia next for their qualifier with Bulgaria, who remain bottom of the group and without a win after a goalless draw with Montenegro.