Serbia recovered from a slow start to hand Slovenia their first defeat, 69-50, at the U18 European Championship Men 2009 in Metz, France.
With the win, Serbia top Group B but Slovenia are also assured of advancing to the Qualifying Round.
Dejan Musli scored 11 of his team-high 13 points after the break as Serbia turned a 29-20 half-time lead into a 54-35 cushion heading into the final quarter.
The Serbian centre's basket with 7:43 left in the period - only his second field goal of the game - gave them their biggest lead up until that point, 33-22, and they kept adding to it the rest of the way.
Slovenia were the quickest out of the gates, going up 9-4 on Jure Besedic's three-pointer and finishing the first quarter in front, 14-13.
But Serbia's perimeter players found their range thereafter and Lazar Radosavljevic's three-pointer in the first minute of the second quarter gave them a 16-14 edge. That seemed to spur them on as they outscored Slovenia 13-6 going into the break.
Radosavljevic and Nemanja Jamaraz finished with 12 points each and Branislav Djekic added 10 points and nine rebounds.