Injured Shelton withdraws, Tiafoe falls as American hopes suffer blow at US Open

Sixth seed Ben Shelton retired from his US Open third-round clash with Frenchman Adrian Mannarino on Friday before 17th seed Frances Tiafoe was knocked out in a big blow to American hopes of ending their 22-year wait for a men's Grand Slam champion.

Twenty-three American men began the tournament looking to win the title and emulate compatriot Andy Roddick, who claimed the Flushing Meadows crown in 2003.

But Friday's shock results meant fourth seed Taylor Fritz was left standing as the country's best title hope at the year's final major after he fought past Swiss Jerome Kym 7-6(3) 6-7(9) 6-4 6-4 at Louis Armstrong Stadium.

Fritz could be joined in the fourth round by Tommy Paul, the only other American man left in the draw, with the 14th seed set to face a tricky challenge when he takes on Kazakh 23rd seed Alexander Bublik at Arthur Ashe Stadium on Saturday.

Shelton grabbed his left shoulder and winced in pain after hitting a forehand early in the fourth set in a tight clash at Louis Armstrong Stadium and pinched at the spot as he prepared to receive a serve from Mannarino in the second game.

"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, before taking a medical timeout midway through the second game in the fourth set.

Shelton later told his father that it was the "worst pain" he had felt in his life, before meeting with the physio again.

He managed to hold his own for a while against left-hander Mannarino, who produced some moments of magic, but looked dejected at the break and shed tears into his towel before pulling out, to gasps from the home crowd.

"When he started having pain, he was leading in the match," said Mannarino, who rallied from a set down to draw level at 3-6 6-3 4-6 6-4 when the match was abandoned.

"He probably would have won. It's unfortunate for him and very lucky for me. I don't really know what to say right now. I suppose I'm happy to get through. I wish him the best."

"I was having good fun on the court - there were some long rallies. I lost some of them, won some of them. It was fun to play. Ben's such an amazing player, it was a great match.

"I was enjoying my time on court, even if I was losing."

American fans were left to swallow another bitter pill around an hour later, when Tiafoe, who last failed to reach the Flushing Meadows fourth round in 2019, crashed to a 6-4 6-3 7-6(7) defeat by Germany's Jan-Lennard Struff on Grandstand.

Struff regained his composure after a flurry of double faults towards the end of the contest to send out last year's semi-finalist.

"I think everybody knows sometimes it's tough to serve out the match," Struff said. "I tried to stay calm and tried to refocus and I managed to get some energy back so I was very happy about that."