Spain's fifth seed and former world number one Carolina Marin breezed into the final of badminton's Thailand Open Saturday, beating South Korea's An Se-young 21-19, 21-15.

The 27-year-old Spaniard, ranked sixth in the world, is aiming for back-to-back titles in this week's tournament – the second of three consecutive events in Bangkok that culminate in next week's World Tour Finals.

She came out on top last week against top-seeded Tai Tzu-ying, and continued her winning streak Saturday, maintaining her signature aggressive play against seventh-seeded An.

She spoke of the mental battle of motivating herself just days after being victorious.

"Sometimes it's tough for the mindset when you win a tournament just three days ago and you have to start a tournament all over again," the reigning Olympic champion said after the match.

The pair had already faced off in last week's tournament, with the more experienced Marin winning in a quick 21-18, 21-16 match.

An, an 18-year-old who was awarded "Most Promising Player" in 2019, was downcast after Saturday's defeat.

"I tried to respond to her smashes and tried everything," said the teenager.

"Unfortunately, it didn't go quite so well, so I'm a little disappointed."

Marin's signature yelps after each match point reverberated around the spectatorless stadium – a coronavirus precaution taken by Thailand as part of its biosecure "bubble" to accommodate players who flew in from across the world.

Despite the efforts of tournament officials, four positive cases have been detected so far, forcing an Indian player and an Egyptian player to withdraw.