Belgium took a perfect 4-0 record into the last eight of the U18 European Championship
Division B in Sofia following a 74-56 victory over Slovakia.
It was far from easy for the Belgians however, who were trailing 41-27 at half-time before an extraordinary fightback in the second half which saw them score 47 points to Slovakia's 15.
Jorn Steinbach led the way for Belgium with 29 points while Miroslav Kral poured in 23 for the losers.
Czech Republic sneaked second spot in Group A with a 94-78 win over Denmark to join Belgium in the next round, where they will form a group with Poland and Sweden.
The Poles secured top spot in Group B with an 83-72 success over their Swedish opponents, despite a game-high 24 points from Jeffery Taylor for the Scandinavians.
Also in Group B, Finland demolished Armenia 133-37 to finish third.
In Group C, Ukraine and Bosnia-Herzegovina secured the top-two places with the former edging to a 71-69 win over their rivals.
Denys Lukashov was the leading player for the Ukrainians with 21 points and seven rebounds.
Switzerland completed a disappointing competition with a 55-49 loss against Ireland to mark their fourth defeat in as many games.
Hungary will be Ukraine's next opponents although they ended their Group D campaign with a 76-61 loss against unbeaten Montenegro.
England failed to win their final group game, slipping to a 71-65 loss against Portugal.