Nick Kyrgios has retired from his second-round Washington Open clash with Tennys Sandgren due to a shoulder injury.
The 22-year-old Australian was losing 6-3 3-0 to the world No.106 American on Wednesday when he pulled the pin after being in obvious discomfort throughout the match.
It was Kyrgios’ first tournament since he retired during the first round of Wimbledon last month due to a chronic hip injury.
He reached the second round in Washington after a bye in the opening round.
Meanwhile, Australian Jordan Thompson has come frustratingly close to upsetting world No.8 Alexander Zverev in the second round.
The 23-year-old Thompson lost 4-6 6-3 7-6 at the ATP event, leading the third-set tiebreak at 5-4 before conceding the final three points of the match.
Two points away from one of the biggest victories of his career, Thompson put a routine backhand into the net and then double-faulted.
Zverev put away the match with a cross-court forehand.
Thompson, ranked 75 in the world, earlier broke his German opponent twice to take the opening set of the pair’s first meeting.
Zverev rallied in the second, taking advantage of the weaker service game of Thompson who won only 36 per cent of points on second serve in the set.
“I’m just happy to get through that one, 7-6 in the third is always something very nice,” Zverev said.
“You feel good about yourself. Hopefully I can do it better the next match.”
Zverev, the winner of three titles in 2017,will face Sandgren in the third round.
Earlier, Australian Marc Polmans lost his second-round match to American Jared Donaldson in straight sets.
The 20-year-old Polmans was beaten 6-2 6-3 by the world No.69.
Tenth-ranked Canadian Milos Raonic also advanced by defeating Nicolas Mahut 7-6 (7-2) 7-6 (10-8).
Raonic, the 2014 Washington Open champion, next faces veteran Marcos Baghdatis.