Alexander Blockx’s impressive US Open 2026 campaign came to an unfortunate end on Wednesday after the Belgian retired from his quarter-final against Karen Khachanov at Flushing Meadows. The 21-year-old was trailing Khachanov 6-2, 7-5, 3-2 when he decided he could not continue. The match lasted one hour and 38 minutes, with Blockx visibly struggling physically for much of the contest.
Why Did Alexander Blockx Retire From US Open 2026?
Blockx entered the quarter-final with a rib injury and was already facing physical concerns before stepping onto the court against Khachanov. Those problems appeared to worsen during the match, making it increasingly difficult for the Belgian to move and compete at his usual level.
The 28th seed was wearing a brace on his right ankle and also had his thigh wrapped. He called for the trainer during the match as he attempted to manage the physical issues and stay in contention against Khachanov.
Blockx continued fighting despite the discomfort, but Khachanov maintained control of the match. Once the Russian moved ahead 6-2, 7-5 and then took a 3-2 lead in the third set, Blockx eventually decided to retire.
Karen is through to the semifinals.
A tough end for Blockx, who retires through injury. Wishing him a speedy recovery ❤️🩹 pic.twitter.com/za9utOpYLV
— US Open Tennis (@usopen) September 9, 2026
There was no indication of a single new injury being confirmed as the reason for his withdrawal. Instead, the Belgian was visibly hampered by a combination of existing and ongoing physical problems, including the rib issue and concerns around his right ankle and thigh.
Karen Khachanov Points Out Alexander Blockx’s Physical Struggle
Khachanov admitted that he could see his opponent was struggling more as the match progressed.
“I was preparing really well for that match up, it’s not easy because I feel I was dominating then I felt he was struggling more and more,” Khachanov said on court.
The Russian said he wanted to maintain his energy despite Blockx’s difficulties and wished the young Belgian a speedy recovery.
“I wish him a speedy recovery but I’m super happy I’m in the semis,” Khachanov added.
Karen Khachanov is into a second US Open semi-final due to a retirement 🤕
His response to Alexander Blockx injury says A LOT about his character!
↳ US Open. Every Match. Live & On Demand.#StanSportAU #USOpen pic.twitter.com/GI2Jl5G01A
— Stan Sport (@StanSportAU) September 9, 2026
Alexander Blockx Makes Belgian US Open History
Despite the disappointing ending, Blockx leaves New York after making history. He became the first Belgian man to reach the US Open quarter-finals.
The 21-year-old’s run was one of the breakthrough stories of the tournament, taking him into his first Grand Slam quarter-final. However, the physical problems that followed him into the match against Khachanov ultimately prevented him from completing the contest.
Khachanov, meanwhile, moves into the US Open semi-finals for the first time since 2022. The world No. 50 had already beaten third seed Felix Auger-Aliassime and 14th seed Learner Tien on his way to the last eight.
He will face either top seed Alexander Zverev or Botic van de Zandschulp in the semi-finals.
