Brazil's Beatriz Haddad Maia won the fourth title of her career with a furious fightback to beat Russian top seed Daria Kasatkina 1-6, 6-4, 6-1 in Sunday's Korea Open final.
Number three seed Haddad Maia lost the opening set in just 26 minutes but turned the tide in the second, before going on to close out the match in a gutsy performance in Seoul.
It was the world number 17's first title since June 2022.
"I know that tennis changes everything very fast," said Haddad Maia.
"I was competing better at the end of the second set and then my tennis appeared. I finished in the way that I wanted and I think I deserved this win."
Kasatkina, ranked 13, has now lost four of her five finals this year.
She said "losing in the final can feel worse than losing in the first round".
"It's tough, especially being up in the final, but she definitely raised the level after the first set," said Kasatkina.
"The match was pretty good but then she was better in the third set."
Neither player had dropped a set on their way to the Seoul decider and both played two matches on Saturday, after heavy rain wiped out the previous day's play.
Kasatkina won her quarter-final after opponent Emma Raducanu retired injured after the first set.
Kasatkina broke Haddad Maia twice on the way to winning the first set.
She broke her opponent again in the first game of the second set and held serve, before Haddad Maia began to threaten for the first time in the match.
The momentum shifted when the 28-year-old Haddad Maia broke back midway through the second set and then took the lead for the first time.
The Brazilian argued a call with the umpire but kept her cool to take the second set.
"I was just trying to play every point," she said.
"I was improving and I think that was the key, to be calm and just play tennis."
Haddad Maia went a break up in the third and stayed ahead as Kasatkina began to crumble.
Haddad Maia broke again and closed out the final when Kasatkina hit a return long.
"I feel stronger, I feel that I'm very competitive now," said Haddad Maia.
"I'm in a good moment, ready for the next week. I feel that I'm doing very good things, working hard.
"Let's see what the end of the season brings to me," she added.
The Korea Open was being played as a WTA 500 tournament for the first time.
Alcaraz fears tennis tour grind will 'kill us:' Carlos Alcaraz hit out at the tennis calendar on Saturday, claiming the schedule is "going to kill us".
The 21-year-old French Open and Wimbledon champion is currently taking part in the Laver Cup, his 14th tournament of the year.
Before arriving in Berlin the Spanish star had already played 50 singles matches in 2024, winning three titles and also collecting a silver medal at the Paris Olympics.
"Probably they are going to kill us in some way," Alcaraz said Saturday after defeating Ben Shelton in straight sets at the Laver Cup.
Alcaraz said that players had different opinions on the topic, but in his view "the calendar is so tight", adding "right now there are a lot of injuries."
"Right now a lot of good players are going to miss a lot of tournaments because of that."
He added that the crowded schedule meant he sometimes struggled to motivate himself on the tour.
"Sometimes, you don't want to go to a tournament. I'm not going to lie -- I have felt this way a few times already.
"Sometimes I don't feel motivated at all. But as I've said many, many times, I play my best tennis when I smile and enjoy it on court. That's the best option to keep motivating (myself)."
At the US Open, where he won his first Grand Slam title in 2022, Alcaraz suffered a shock second-round exit to 74th-ranked Botic van de Zandschulp.
He admitted he had blundered by not taking a longer break between the Olympics and New York.
At the Paris Games, he lost an emotionally-draining gold medal match to Novak Djokovic, just weeks after sweeping the Serb off court to successfully defend his Wimbledon title.
"I took a little break after the Olympic Games. I thought it was enough. Probably it wasn't enough. Probably I came here without as much energy as I thought I was going to (have)," he said after his US Open horror show.
"I have to think about it and I have to learn about it."
Agence France-Presse