Katerina Siniakova of the Czech Republic clinched the Bastad clay court title on Sunday with a 6-3, 6-4 win over Caroline Wozniacki who has now lost five finals in 2017.
For 21-year-old Siniakova, the world number 56, it was a second career title after her maiden triumph in Shenzhen last year.
"It's really amazing for me," said Siniakova, who was runner-up at the Swedish venue in 2016.
"Last year was really good, and so I'm so happy that I came back because I couldn't imagine a better week."
Heavy rain delayed the final by more than two hours before the action was further disrupted by medical time-outs for both players.
Wozniacki, who has a season-leading 42 wins under her belt, was aiming to take home her first title after finishing runner-up in Doha, Dubai, Miami, and Eastbourne.
However, her efforts were not helped by a right elbow injury which contributed to 39 unforced errors to just 19 winners.
"It was a tough match. Katerina played very well, so congratulations on winning the title," the former world number one told wtatour.com.
"I'm looking forward to the US Open Series and the US Open. It's one of the tournaments where I've done my best, and it's one of my favourite tournaments of the year. I'm excited to go back, see how I can do on the hardcourts and hopefully finish the year strongly."