Frenchman Gael Monfils fell victim to an abdominal muscle injury and retired from the ATP Winston-Salem final handing Austrian Jurgen Melzer the crown.
Melzer was leading 6-3 2-1 - and was up a break in the second set - when Monfils called it quits after consulting with a trainer.
The latest of the injury hard luck that has followed flamboyant shot-maker Monfils throughout his career comes with the start of the US Open, the last Grand Slam of the season, starting on Monday in New York.
The 15th seed plainly felt the injury while serving in the third game of the second set, after dropping the first set in 33 minutes to his 32-year-old opponent.
He was broken in a game that went to deuce four times, reduced to leaning on his racquet after each point in the final game.
He was visited by the trainer on court but opted not to continue, giving Melzer his fifth career title and first on hardcourt.
"I'm a little bit sad. I'm a big fighter and I wanted to make it today," said Monfils, who had also been bidding for a fifth title. "I felt great this week and was playing good tennis.
"It was my first time here and I had played quite well. I had some tough matches and played quite well. I'm now just hoping for a speedy recovery for the US Open."
Monfils had also been treated for muscle pain and tightness during his semi-final win on Friday over Alexandr Dolgopolov.
The world number 43 hadn't played for a month prior to this week after an ankle injury suffered in training forced him to miss the Montreal and Cincinnati Masters.
Monfils was playing in only his fifth event since a runner-up finish in Nice, staged the week before the French Open in May.
The injuries have slowed Monfils' bid to rebuild his ranking. He had fallen as low as 108th in early February but has climbed back into the top 50 by reaching the quarter-finals or better seven times this season.
He now stands 29-17 for 2013 and is fighting to be fit for a first-round match at Flushing Meadows against Romanian Adrian Ungur.
Melzer, who missed a month after Wimbledon with a shoulder injury, said taking on Spain's Gala Blanco as his coach was paying dividends.
"I'm very happy to win this title, I was not happy with first-round losses at Montreal and Cincinnati, I did not perform well," he said.
"But I really had a great week here. I'm very sorry for Gael. He has such a big heart and is such a fighter. When he retires from a match, you know something is wrong. I wish him a speedy recovery for the Open."
Melzer began the match with a break for a 2-0 lead. Monfils saved a set point in the eighth game to narrow the gap to 5-3, but the experienced Austrian delivered a service winner to pocket the set on his third opportunity in the next game.
