Denmark's Holger Rune saw off top seed Stefanos Tsitsipas in straight sets in Stockholm on Sunday to claim his second ATP title at the age of just 19.
The world number 27 saved the only break point he faced in an impressive 6-4, 6-4 victory.
"It was an unbelievable match from my side," Rune said after adding to the maiden Tour title he won in Munich earlier this year.
"I knew it was going to be difficult, but I just tried to stick to the game plan. I had to play my best tennis today and it was good that I could find the level. I am super happy."
Rune broke in the third game of each set, finishing the match with 20 winners.