England manager Gareth Southgate blamed fatigue from a long season as the Three Lions slumped to their first defeat against Hungary in 60 years on Saturday as the hosts earned a shock 1-0 win in Budapest.
Dominik Szoboszlai scored the only goal from the penalty spot as Hungary celebrated their first victory over England since 1962.
Defeat on penalties to Italy in the Euro 2020 final was the only time Gareth Southgate's side had been beaten in their previous 22 games.
However, an experimental side failed to trouble the hosts, who were roared on by a 30,000 crowd largely consisting of school children.
"They are bitterly disappointed because we want to keep winning matches. If we want to be a team right at the top tier of football, we need to come here and win," said Southgate.
"It has been a long season. The heat was a factor and took a lot out of the players."
Hungary were forced to play the game behind closed doors due to the behaviour of fans during their home matches at Euro 2020.
UEFA guidelines allow children under the age of 14 to be given free tickets under such circumstances and the Hungarian Football Federation took full advantage.
Southgate handed senior debuts to Jarrod Bowen and James Justin, but the visitors never got going.
Hungary created the better of the chances, Szoboszlai seeing an effort cleared off the line by Conor Coady and captain Adam Szalai's ambitious effort from just inside the England half dropping just wide after he spotted Jordan Pickford off his line.
The home side's pressure paid off when they were awarded a penalty on 64 minutes as substitute Reece James was adjudged to have fouled Zsolt Nagy after the Hungarian left-back controlled a pass in the area.
James was booked as RB Leipzig forward Szoboszlai made no mistake from the spot to put the hosts ahead.
"We did not create too many clear-cut chances and the actual result hinged on a decision which is harsh but probably won't be overturned," added Southgate.
"The balance of finding out about new things and the consistency of the regular team, I have to look at whether I got that right."
Harry Kane nearly salvaged a point in stoppage time but was inches away from his 50th international goal as his powerful effort flew into the side-netting.
Southgate's men now have to raise themselves for a trip to Germany on Tuesday before hosting Italy and Hungary later this month.