Greece and Finland won their semi-finals on Sunday at the U16 European Championship Division B in Bulgaria to clinch promotion.
The two sides will now go for gold in Monday's final.
The Greeks defeated Romania 60-57 in overtime after a superb effort from Artemis Spanou, who had 17 points and 17 rebounds.
Romania had forced the extra period when Alexandra Florea made a three-pointer right at the end of regulation.
Once in the overtime, Greece made six consecutive free throws - four by Christina Navrozidou - to take the lead for good.
Romania's Cristina Bigica had 19 points to lead all scorers
For Finland, Janniina Koivunen had 23 points and 10 rebounds in a 58-44 win over Slovenia.
The Finns outscored the Slovenians 19-4 in the second quarter for a 36-18 lead at half-time and cruised to victory.