Sixth seed Ben Shelton retired injured from his U.S. Open third-round match against France’s Adrian Mannarino on Friday, ending American hopes of a home champion.

Shelton exited while the match was level at two sets apiece on Louis Armstrong Stadium, suffering from an apparent left shoulder injury early in the fourth set.

The 22-year-old winced in pain after striking a forehand, then clutched his shoulder while preparing to receive serve in the second game of the fourth set.

“I just did something to my shoulder. I don’t know what it is. I’m in a lot of pain,” Shelton told his father and coach, Bryan Shelton.

He received treatment during a medical timeout but later told his father the pain was the “worst” he had ever experienced, before continuing briefly on court.

Despite the pain, Shelton stayed competitive, but Mannarino found rhythm, showcasing skill and variety against the American crowd favourite.

Shelton, touted as a strong title contender, was visibly emotional, crying into his towel before retiring to gasps from the home crowd.

The 2003 title by Andy Roddick remains the last time an American man won at Flushing Meadows.

“When he started to feel pain, he was leading. He probably would’ve won,” said Mannarino, who trailed two sets to one before levelling 3-6, 6-3, 4-6, 6-4.

“It’s lucky for me, unlucky for him. I wish him a quick recovery,” Mannarino added during his post-match interview.

The French veteran praised Shelton’s game, calling him “amazing” and said he enjoyed the intense rallies despite trailing for much of the match.

Mannarino advances to the fourth round, while Shelton exits the tournament in disappointment after showing strong early form.