The world No 2 pair, who have now secured a record three titles in a year, won 22-20, 21-19 in a match lasting 54 minutes at the Kumamoto Prefectural Gymnasium.

The first game was reminiscent of their semi-final tie against another Japanese pair yesterday, when they came from being three game points down at 17-20 before going on to win the match.

Pearly-Thinaah, who now sit on top of the World Tour Finals (WTF) qualifiers list, won US$37,525 (RM155,190) while the runners-up took home US$18,050 (RM76,648).

The Malaysian pair have now beaten Iwanaga-Nakamishi seven times in their nine encounters to date.

Pearly-Thinaah are enjoying a brilliant season in which they have qualified for seven finals, equalling that of men’s doubles pair Razif Sidek-Jailani Sidek in 1989.

Men’s singles ace Lee Chong Wei holds the record for the best season, however, with 11 final appearances in 2010.

Pearly-Thinaah won the Arctic Open and Thailand Open titles this year. They lifted the Swiss Open crown in 2021, French Open (2022) and Hong Kong Open (2024).

They were also runners-up at the World Championships in Paris this year, losing to world No 1 pair from China Liu Sheng Shu-Tan Ning.

The duo will be playing their last tournament before the WTF at the Australia Open in Sydney next week. They will meet Indonesia’s Febriana Dwipuji Kusuma-Meilysa Trias Puspitasari in the opening round.

They will be among the favourites to lift the women’s doubles title at the RM12.5 million WTF to be played in Hangzhou, China, from from Dec 17 to 21.

The other Malaysians who have made it to the WTF are men’s doubles pairs Aaron Chia-Soh Wooi Yik and Man Wei Chong-Tee Kai Wun, and mixed doubles shuttlers Chen Tang Jie-Toh Ee Wei and Goh Soon Huat-Shevon Lai Jemie.