World number one Tai Tzu-ying fought back from behind to beat Indian star PV Sindhu in three games at badminton's World Tour Finals in Bangkok on Wednesday.
The 26-year-old Taiwanese champion lost the first game 19-21 against Sindhu, the Rio Olympics silver medallist, before regrouping to win the next games 21-12, 21-17.
"It was a good match, there were no easy points," said Tai, who will face further tough assignments against Thailand's former world champion Ratchanok Intanon and an in-form Pornpawee Chochuwong.
Chochuwong, ranked thirteenth, upset the fifth seed Intanon in a three-game cliffhanger 15-21, 21-11, 21-18.
"I put a lot of pressure on myself and really felt I couldn't play my best," Intanon said.
Elsewhere Carolina Marin, looking for her third straight trophy of badminton's three-tournament restart, dispatched Russia's Evgeniya Kosetskaya 21-19, 21-14 in 40 minutes.
"The first game was tough after winning two back-to-back titles," said the reigning Olympic champion.
"Sometimes for your mindset, it's tough to be ready again for a new week, a new match and a new tournament."
In the men's singles, Taiwanese second seed Chou Tien-chen held on in three games over Malaysia's Lee Zii Jia 21-16, 12-21, 21-11.
But hotel quarantine is taking its toll on Hong Kong's eighth-ranked Angus Ng Ka Long, who lost to twelfth-ranked Wang Tzu-wei from Taiwan 21-10, 21-14.
"I feel that I couldn't perform my best today. I'm struggling to find that 'on court feeling'," Ng said.
"It's hard to find the rhythm again. I'm struggling with my mind being in the same venue, same hotel and the same place for so long."
Third seed Anders Antonsen triumphed in three games against former world number one Srikanth Kidambi from India 15-21, 21-16, 21-18.
His fellow Dane Viktor Axelsen clocked up his 26th match win in a row, against Indonesia's Anthony Ginting, 21-17, 21-8.
Axelsen is also hoping for a tournament hat-trick in Bangkok.
The delayed 2020 season finale, starting Wednesday, is the third tournament behind closed doors in three weeks in Bangkok, as badminton resumes after months of coronavirus cancellations.
The top eight players in each discipline are contesting this week's tournament, although China and Japan had to pull out because of coronavirus problems.
Despite the strict biosecurity arrangements, four people inside the tournament "bubble" have tested positive, including two players who were forced to withdraw.