Thailand's Pornpawee Chochuwong defeated Olympic champion Carolina Marin at the Barcelona Spain Masters 2020.
The reigning Olympic champion lost 21-11, 16-21, 18-21 in the final.
The Spanish shuttler rushed to emergencies last week to be by her father's side after an accident at home. He remains in hospital in her home town of Huelva in southern Spain.
Currently ranked 8th in the world, Marin started strongly but was overtaken by a worthy winner.
The crowd in Barcelona got right behind the Spanish star, as they have done all tournament, urging her on to victory, but a first title of the year will have to wait.
"Sometimes it's hard to put everything out of your mind, but it's best just to accept and go with it. My whole family is supporting me and I know my father was listening to the match today," said Marin after she beat Thailand's Supanida Katethong 21-16, 21-16 in the semi-final.
Unhappy with her play, Marin said she felt "lacking in important details and concentration," before the final.
So it went in the final, the Spanish star losing her way after the first set.
Cruising to a first set victory Marin looked certain to bring her record to 6-0 over her Thai opponent in the final, but Chochuwong found her feet, leading for most of the second set before eventually claiming it 16-21.
Uncharacteristic, unforced errors crept into Marin's game and the Thai challenger sensed an opportunity to get her first ever win against Marin.
The Spaniard drew strength from the partisan crowd in the Catalan capital, and brought her combative style to the court, celebrating points vocally and pumping her fists, but cracks appeared too, showing her disappointment and frustration at increasing errors.
Locked at 9-9 in the second set, a monster 42-point rally went Chochuwong's way, Marin dropping another short and into the net to give her opponent a two-point lead.
Faces began to look worried in the crowd as Marin fought to maintain her customary calm.
She steadied the ship with a big smash to make it a one point game once more, 10-11, but the Thai shuttler realised that keeping the rallies as long as possible was in her interest, Marin finding the net twice more in quick succession.
Trailing 11-15 at one point, Marin brought it back to 16-17 but Chochuwong pressed home her advantage winning 18-21 to take the match.
It's a big victory for the 22-year-old Thai player, defeating the Rio 2016 champ for the first time ever.
Marin was below her best which was perhaps understandable considering the couple of weeks she's had.
The Spanish shuttler rushed home from France almost two weeks ago, where she was with the national side at the European Team Badminton Championships, after her father suffered a serious head injury in a fall at home.
She was due to debut with the Ibiza team CB Pitius in the Spanish national league last week, but cancelled to be with her family and by her father's side.
Making the final in Barcelona could be considered a positive result considering the circumstances.
Wins at the China Open in September 2019, the India Syed Modi International and the Italian International in December, and runner-up finishes at the 2019 French Open and the 2020 Indonesian Open have Marin fans believing that she can get back to her best before the biggest challenge of her career so far:
Defending her Olympic title at Tokyo 2020.