World number 51 Nuno Borges beat Rafael Nadal 6-3 6-2 to win the Swedish Open in Bastad.
Spaniard Nadal, a 22-time Grand Slam champion, slipped to a resounding defeat in his first final since 2022.
Hampered by injury in recent years, the 38-year-old has fallen to 261 in the rankings and opted against playing at Wimbledon this summer to prioritise the Olympics.
Portuguese Borges, playing his first ATP final compared to Nadal's 131st, took the first set in 46 minutes and won three games in a row in the second to seal victory.
"It's crazy.