BUENOS AIRES, Oct. 14 (Xinhua) -- Australia clinched top spot in their group at the girls' 3x3 Youth Olympics basketball tournament here despite a shock loss to Spain on Sunday.

The Oceania outfit succumbed 12-7 to the European side early in the day before beating Estonia 19-15 in their second and final group match.

"Our defeat made us sad, but we kept playing our game and qualified," said Australian Suzi Rose Deegan after scoring nine points against Estonia.

The Netherlands finished second in Group D by beating the Czech Republic 16-10 and then Spain 14-12 in their last preliminary games.

"We're advancing step by step. Each one of us gave her best and we achieved our goal," said Dutch player Zoe Slagter.

In the boys' competition, Belgium kept their unbeaten record intact by defeating Kyrgyzstan 21-11 and Italy 18-16.

Tuesday's quarterfinals will feature Ukraine vs Italy, Slovenia vs Russia, Belgium vs Brazil and Argentina vs Georgia in the boys' competition and Hungary vs France, Ukraine vs Australia, United States vs Netherlands and Argentina vs China in the girls' tournament.