Thailand is hosting three consecutive badminton tournaments in a bio-secure coronavirus bubble, without spectators.
Former world champion Marin, 27, went into Sunday’s final without losing a single game across the two tournaments.
In a much tighter contest than the first final last week, the Spaniard claimed the first game 21-19.
The Taiwanese 26-year-old appeared to lose her confidence early in the second set, as a dangerous Marin asserted her dominance.
Tai saved four match points but her comeback was too little too late as Marin sealed her victory 21-17.
𝗧𝗥𝗜𝗩𝗜𝗔After over 5⃣ years, @CarolinaMarin bags consecutive straight games victories over Tai Tzu Ying. She last… https://t.co/SyRRlGcb4M
— BWF (@bwfmedia) 1611476100000
“I feel extremely happy. Two victories in two weeks, it’s an amazing way to start the year,” said Marin.
“I said to myself and my team that for 2021 I was going to be a new player, with a new mindset with more focus on the game.”
The first non-Asian women’s player to win an Olympic badminton gold, Marin has faced an uphill battle to recover from a January 2019 knee injury in time to defend her crown in Tokyo.
The men’s final will see two Danes face off — fourth seed Viktor Axelsen and Hans-Kristian Solberg Vittinghus.
Solberg Vittinghus, ranked 42, made the tournament from a reserves list and had to cancel a flight home because he had not anticipated a finals berth.
The women’s doubles was an all Korean affair with sixth-ranked Kim So-yeong and Kong Hee-yong too strong against fourth-ranked Lee So-hee and Shin Seung-chan 21-18, 21-19.
In the men’s doubles, seventh-ranked Lee Yang and Wang Chi-Lin of Taiwan also made it back-to-back titles in 36 minutes against Malaysia’s ninth-ranked Aaron Chia and Soh Wooi Yik 21-13, 21-18.
In the mixed doubles, Thailand’s third seeds Sapsiree Taerattanachai and Dechapol Puavaranukroh will play sixth-ranked Koreans Seo Seung-ae and Chae Yujung.
Four people involved in the tournaments, including two players, have tested positive for the coronavirus during the past fortnight of competition.
The finale — the Badminton World Federation World Tour Finals — kicks off on Wednesday at the Impact Arena and will be contested by the top eight of each discipline.
Chinese and Japanese athletes have not participated in the Bangkok tournaments.