The Grimalts - who are cousins - outlasted the challenge of the United States pairing of Casey Patterson and Stafford Slick to win 23-21, 21-15 in this latest leg of the International Volleyball Federation (FIVB) event which offers a snapshot of what things might look like in Japan’s capital during the 2020 Olympics.

"It was a really tough match,” Esteban said. “In the first set, we served really bad but we kept fighting and withstood the wind.

"We will go for the gold, but we will do it point by point," Marco said.

The Serbians will have an opportunity to improve on their Lucerne 3-star silver medal finish after a 21-18, 21-14 win against Germany’s Philipp Arne Bergmann and Yannick Harms.

"I’m really excited because we are in the finals," Basta said.

"It’s a great success for us in this tournament.

"This is our second World Tour 3-star final this year, so we are satisfied with the victory."

Finland’s Taru Lahti-Liukkonen and Anniina Parkkinen became the first to reach the women’s semi-finals thanks to a 21-18, 21-11 win against home pair Yui Nagata and Minori Kumada.

Lahti and Parkinen have won all their matches in straight sets en route to their first World Tour final four appearance after eight previous events.

"This is our first time in the semi-finals as a team, so it feels really nice to make it this far," Parkkinen said.

"We are really happy that we won the match," Lahti added.

"We knew that if we play our own strong game then we have a good chance to win.

"Today we made a good job on block and defence."

Earlier, the Finnish pair had defeated Thailand’s Rumpaipruet Numwong and Khanittha Hongpak 21-15, 21-12 in the round of 16.