Croatia boys’ captain Darko Klaic is focused on marginal gains as his team prepare to face USA in the semi-finals of the ITF World Junior Tennis Finals in Prostejov.

In the immediate aftermath of his side’s last-eight victory over Brazil, Klaic was on-court conducting an impromptu coaching session with doubles duo Dino Prizmic and Patrik Jurina, who had just succumbed to Gustavo Tedesco dos Santos and Lucas Andrade da Silva.

Croatia had already secured their place in the semi-finals following singles joy for Jurina and Prizmic against Dos Santos and Da Silva respectively. Klaic, however, was of the view that improvements are needed if his side are to be crowned ITF World Junior Tennis champions for the first time.

“There is always something to work on because they are young and developing. Sometimes they are stubborn and cannot understand certain things so I have to explain,” Klaic told itftennis.com.

“We were very strong in singles and we played some good tennis. The Brazilian players are really good, especially the No. 1 [Dos Santos], so the boys had some tough matches and they played very well. In doubles, they are still trying to find themselves and need to work more.

“We rarely win easily and doubles tends to be decisive. It is very important to play good doubles especially with the USA tomorrow likely to be stronger than Brazil. It’s the semi-finals so they will be fired up and everyone really needs to play at their best level if we want to win.”

In what was a recurring theme in the boys’ draw – all four quarter-final ties were concluded by the time of the doubles – defending champions and No. 2 seeds USA confirmed their place in the last four courtesy of a strong singles showing in a 2-1 victory over Japan.

Nishesh Basavareddy defeated Shogo Sanada 6-1 6-0, while Kyle Kang dispatched Lennon Roark Jones 6-3 6-2. Yu Maeda and Sanada then restored a modicum of pride for Japan by overcoming Basavareddy and Kang in the doubles.

USA are now just one tie away from the final and a shot at a sixth ITF World Junior Tennis gong. Should they top the podium, they would become only the second boys’ side in the history of the competition to retain their title – after the USA side of 2003.

No. 1 seeds Czech Republic, meanwhile, made light work of Argentina to reach the last four, defeating their South American rivals 3-0. Jacub Mensik and Vojtech Petr overpowered Giuliano Furlotti and Nahuel Nicolas Eli respectively in the singles to ensure victory. Mensik and Lukas Velik then combined to win the doubles.

The Czech boys look a formidable proposition on the clay of the TK Plus Centre as they bid for their maiden ITF World Junior Tennis title. Jiri Kulich’s outfit now face France, who overcame Bulgaria on Centre Court, in the semi-finals.

France were in dominant mood from the start as Gabriel Debru disposed of Viktor Markov 7-6(2) 2-6 6-3 in the opening singles rubber, which was swiftly followed by a 7-5 7-5 triumph for Antoine Ghibaudo over Adriano Dzhenev in the second.

Bulgaria hit back in the doubles as Markov and Ilyan Radulov prevailed. Despite defeat today, Bulgaria captain Aleks Martinski refused to be too downbeat.

“I am very happy to be at this tournament with these boys and I’m also pleased with the level of fight my team has shown,” Martinski told itftennis.com.

“We lost today but we played some good tennis and managed to win the doubles. It’s a learning process and we have to work hard. Hopefully this tournament will act as motivation for the boys.”

In the play-off draw, there were victories for Romania, Canada, Peru and Germany over China, Thailand, Australia and Egypt respectively.