Prague - England captain Harry Kane said there was no need to panic after losing a first qualifier in 10 years 2-1 to the Czech Republic on Friday, but admitted defeat is a wake-up call ahead of next summer's European championships.
The Three Lions are still well-placed to qualify as they top Group A thanks to a better head-to-head record against the Czechs after winning the first meeting between the sides 5-0 at Wembley in March.
However, England are aiming to go even further than the semi-final stage they reached at the World Cup and Nations League in the past two years and will need to improve markedly on an error-strewn performance in Prague.
"It was down to us. We had the perfect start but we were sloppy with the ball and they scored soon after," said Kane, whose fifth-minute penalty was quickly cancelled out by Jakub Brabec.
Zdenek Ondrasek struck the winner five minutes from time to end England's 43-match unbeaten run in Europan championship and World Cup qualifiers stretching back to 2009.
"We weren't fighting and pressing as much as we normally do," added Kane.
"The second-half was a bit better but we didn't take a couple of chances. It's a bit of a wake-up call.
"We're still in a good position so there's no need to panic, but we've still got stuff to work on, as you could see tonight."
England could still qualify as soon as Monday with victory away to Bulgaria as long as Kosovo do not beat Montenegro on the same night.