Tanongsak Saensomboonsuk dedicated his breakthrough men's singles title to the late King of Thailand after winning gold at the Badminton World Federation (BWF) Denmark Open in Odense today.
The world number 18 battled past seventh-ranked opponent Son Wan-ho of South Korea 21-13, 23-21 at the Arena Fyn.
He emotionally dedicated his victory to the recently deceased royal afterwards.
King Bhumibol had been the world's longest reigning monarch when he died aged 88 after 70 years on the throne earlier this month.
Thailand remains in an official mourning period.
There was also success for Denmark on finals day, as the hosts secured a first victory in the annual event since 2011.
It was Joachim Fischer Nielsen and Christinna Pedersen, the same pair who triumphed five years ago, who secured a spot on the winners podium in the mixed doubles.
The "Great Danes" triumphed 21-16, 22-20 over Chinese rising stars Zheng Siwe and Chen Qingchen to trigger frenzied celebrations among family, friends and fans.
Olympic champions Misaki Matsutomo and Ayaka Takahashi claimed a less surprising victory in the women's doubles event.
The Japanese duo beat South Korea's Jung Kyng Eun and Shin Seung Chan, 19-21 21-11, 21-16.
Akane Yamaguchi secured a second gold for Japan in the women's singles final courtesy of a 19-21, 21-14, 21-12 win over Tai Tzu-ying of Chinese Taipei.
Rio 2016 silver medallists Goh V Shem and Tan Wee Kiong of Malaysia also continued the southeast Asian success by securing their first ever title on the MetLife BWF World Superseries tour.
They survived two match points to beat Thailand's Bodin Isara and Nipitphon Phuangphuapet, 14-21, 22-20, 21-19, in the men's doubles final.