Czech Republic set themselves up for a potential clash with Russia to decide to spot in Group C after beating Belgium 74-61 on Saturday.
Lubos Barton and Jiri Welsch keyed an 11-0 fourth quarter run by the Czechs which turned a 56-52 lead into 66-52 with four minutes to play.
Barton had 10 points in the first quarter as the Czechs raced out to a 21-14 lead.
But Belgium's victory over Russia proved that they are a team to be reckoned with, and they never let the Czechs get out of sight.
After scoring 31 and 21 points in his first two outings for his country, Welsch has struggled. He scored 10 points in a loss to Russia and just 8 against Belgium.
However, the 197 cm guard found his shot at just the right moment and his jumper followed by two free throws opened up a 61-52 lead in the final quarter.
Pavel Benes added a three-pointer and a three-point play from Barton gave the Czechs a 66-52 lead and put the game out of reach for Belgium.
Petr Benda and Barton both finished with 16 points for Czech Republic who face Hungary next Wednesday.
If they beat the Hungarians and Russia defeat Belgium, Czech Republic will play Russia on 16th September in Opava in what will be a winner-takes-all game.