The Thai duo went down to the fourth ranked Japanese pair 18-21, 9-21 in the final of the World Tour Super 1000 event at Odense Sports Park, that lasted only 37 minutes, the Badminton Association of Thailand said on Monday.
The Thai second seeds received US$2,9750 (B993,650) as runners-up. They lost in the final in the same tournament in 2018.
Dechapol and Sapsiree advanced to the final after they came from behind to defeat third seeds Indonesia 16-21, 21-17, 22-20 on Saturday.
The Thai duo rallied to defeat the Indonesian third seeds and 2019 champions Praveen Jordan and Melati Oktavianti 16-21, 21-17, 22-20 in a thrilling semi-final.
The battle was very close as Dechapol and Sapsiree won a total of 59 points while the Indonesian pair took 58 in the 65-minute contest.
It was also the first time the Thai pair dropped a game during the tournament, prior to the final against Japan.
Elsewhere, fifth seeds Jongkolphan Kititharakul and Rawinda Prajongjai, the other Thai players in the tournament, were overpowered by China’s Huang Dongping and Zheng Yu in the women’s doubles semi-final with the newly paired Chinese duo taking a straight win of 21-10, 21-15.
Huang and Zheng defeated second seeds Lee So-hee and Shin Seung-chan of South Korea in straight sets 21-15, 21-17 in the final on Sunday.