Last year's European Championships finalists Serbia and Spain on Saturday booked their places in the first quarterfinal at the basketball world championships.
Spain prevailed at the European event, but a young Serbian team makes them a more formidable opponent this time round.
Serbia reached the quarterfinals with a last-second 73-72 win over Croatia while Spain saw off Greece 80-72.
Taking a slender one-point lead into the final quarter, Serbia saw Croatia to surge back into contention as Marko Popovic went on a final-quarter 14-point scoring spree to tie the teams up.
When Popovic landed a free-throw with five seconds remaining, the scores were tied at 72-72, but crucially it left the Serbians enough time to run one more offensive play.
Alexsandr Rasic was fouled in the last seconds and made the first but missed the second with Croatia grabbing the rebound, but it was too late for the Croatians who could not get off a proper shot, giving the Serbians the win.
Since returning from suspension Serbian captain Nenad Krstic of Oklahoma City Thunder has been integral for his team, leading with 16 points on Saturday.
Following the game Serb coach Dusan Ivkovic spoke of the importance of Krstic.
"Nenad has a big personality and is a very important part of the team. I think the last three games (since returning from suspension) he has fought very hard and I wish for that to continue," said the coach.
Ivkovic was very proud of how well his young team fought.
"In four days we have had three very tough games against Australia, Argentina and Croatia so I want to congratulate my players. The three days of rest now is very important," he said.
Greece's inability to beat Spain in major tournaments continued as they again fell short against the European champions 80-72.
Rudy Fernandez and Juan Carlos Navarro stepped up, scoring 22 and 14 points respectively.
Spanish player Ricky Rubio talked of the respect his side hold for Serbia.
"They are very young but very talented. Tonight they proved they are ambitious - it will be a strong rivalry."
