BANGKOK (AFP) - Reigning Olympic badminton champion Carolina Marin on Sunday (Jan 24) claimed her second Thailand Open title in a fortnight against the same opponent - women's singles top seed Tai Tzu-ying.

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 game, 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.

"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 retain her crown in Tokyo.

The women's doubles was an all-Korean affair with sixth-ranked Kim So-yeong and Kong Hee-yong too strong for fourth-ranked Lee So-hee and Shin Seung-chan, winning 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 after 36 minutes against Malaysia's ninth-ranked Aaron Chia and Soh Wooi Yik 21-13, 21-18.

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.