Frenchman Nicolas Mahut won his first ATP title thanks to a comfortable 6-3 6-4 victory over favourite Stanislas Wawrinka in Den Bosch.
The 31-year-old, whose ranking has slipped to 240th in the world after a knee injury, was appearing in just his third final.
The match was disrupted by rain twice in the first set, but Mahut, appearing in his first final since 2007, dealt with the interruptions the better.
Mahut broke the Swiss star, ranked 10 in the world, on their return to take a 5-3 lead and had no problem in wrapping up the set.
He then broke Wawrinka in the third game of the second set and kept his nerve to seal victory and end the tournament without having dropped a set.
Mahut's victory on grass capped a comeback from a career-threatening knee injury that sidelined him for months.
"Six months ago, I was not sure I could play again on the tour and here I am with the trophy," he said. "I am really proud with the way I played all week.
"After all the difficulties these past few months this win proves that I was right to keep going.
Mahut, who was a runner-up in the men's doubles final at the French Open with Michael Llodra, was given a wild card entry for Wimbledon and will play Czech Jan Hajek in the first round.