FRANKFURT, Germany - Ivan Schranz scored Slovakia’s quickest goal at a major tournament to take his side to a gritty 1-0 victory over a wasteful Belgium in the European Championship on Monday, providing the first upset of the continental finals in Germany.

It was Belgium's first loss in 16 games under coach Domenico Tedesco and a flashback to their calamitous 2022 World Cup campaign on a day when whatever could go wrong in the Group E encounter, did, though much of their misfortunate was self-inflicted.

They had two disallowed goals from the boot of Romelu Lukaku, the first for offside and the second a handball in the build-up on a hugely frustrating day for the burly striker in which he also missed several clear-cut chances.

Belgium were without their preferred central defensive pairing of Jan Vertonghen and Arthur Theate and with left winger Jeremy Doku playing on the right in the first half and Yannick Carrasco as a left wing back, there was a lack of balance to the team

"It is a pity. The first 20 minutes we were really good and we make such a mistake for which we are punished," Belgium captain Kevin de Bruyne said.

"In the second half it was better, we upped the tempo. We deserved to win but did not score and that is the way it is.

"Apart from a few other chances we didn't give much away. We adjusted some things at halftime and then played well. We pushed, we created chances. We certainly deserved to at least a draw because we didn't play badly."

Slovakia joined Romania at the top of the standings after their 3-0 win over Ukraine in Munich earlier on Monday. Belgium next meet Romania in Cologne on Saturday.

There had been talk before the game of this being a new Belgium, casting off the Golden Generation tag and filled with young talent, but the same problems persist.

Tedesco’s side dominated the 90 minutes, but lacked a clinical touch and when they did find it they were denied by the VAR and scrambling Slovakia defense.

Belgium were without their preferred central defensive pairing of Jan Vertonghen and Arthur Theate and with left winger Jeremy Doku playing on the right in the first half and Yannick Carrasco as a left wing back, there was a lack of balance to the team.

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It was that uncertainty that led to Slovakia’s opener as Doku’s poor ball into his own box was not dealt with by the defense and when Juraj Kucka’s effort was saved, Schranz beat Belgium goalkeeper Koen Casteels from a tight angle with his record-breaking goal timed at six minutes and five seconds.

Belgium will feel they should have been 1-0 up already by then as Lukaku was foiled from point-blank range by Slovakia goalkeeper Martin Dubravka after Doku’s mesmerizing run from his own half.

That was the first of three big chances in the half for Lukaku, who had scored 17 goals in 11 games under Tedesco.

Slovakia had opportunities too. Casteels had to make a superb diving save from Lukas Haraslin’s excellent volley, before they showed excellent defensive discipline and every tackle was celebrated by the Slovak players as if they had scored a goal.

Belgium came close again when a goalmouth scramble ended with substitute Johan Bakayoko shooting for what seemed a certain goal, only for Slovakia defender David Hancko to clear the ball off the line.

Lois Openda then handled the ball after his persistence on the left-hand side had set up Lukaku to finish.

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"It's a huge victory," Dubravka said. "We worked hard and fought until the end. You need to be a little bit lucky in games like this and we were.

"We came into the tournament feeling great and this will give us plenty of strength."