Khachanov Reaches US Open Semifinal as Blockx Retires Midway Through the Third Set

When Alexander Blockx set his racket down midway through the third set, the loudest sound on court did not come from the stands. It was medical tape being peeled off skin. The scoreboard stopped at 6-2, 7-5, 3-2 in favour of Karen Khachanov, and the Russian stood at the baseline for a long moment before walking to the net to shake hands. A Grand Slam quarterfinal that ends this way always leaves behind an emptiness of its own, and that emptiness does not belong to the man who advanced.

An empty court, it turns out, has its own sound, and that sound is memory.

Blockx, the No. 28 seed, walked into this match carrying every opportunity of a young player who had just come through a long fortnight. His upper left leg was wrapped. He received treatment on his lower leg and on his back, two places that are not adjacent, which is the most worrying signal a hard-court week can produce. When a body has to manage two separate pain points at once, it is already compensating, and every form of compensation opens a road to a new injury.

Before they are a semifinal berth, they are children carrying a dream away from home. Blockx grew up inside a Belgian development system that has never favoured the patient defender. Khachanov left Russia very young to hit balls on European hard courts. Two different journeys met on the same afternoon, and only one of them still had the resources to continue.

Khachanov reaches the semifinal as an unseeded player, and this is the third time he has made the last four at a Grand Slam. He was a US Open semifinalist in 2026 and an Australian Open semifinalist in 2026. The gap between that last appearance and this one runs past three years, long enough for a player in his thirties to be filed away by collective memory under the heading of past his peak.

Based on my experience covering matches across several Grand Slam seasons, most retirements do not come from a single collision. They come from an accumulation: a five-setter in the third round, a training session cut short, a night of broken sleep because of the schedule. By the time a player calls the trainer, the body made the decision long before.

The first set ended 6-2, and the margin did not come from highlight-reel shots. It came from court position. Khachanov served deep into the middle of the box, forcing Blockx to reply with a high-spin return, then stepped inside the baseline and drove his backhand down the line. A player with a compromised leg cannot change direction three times inside one long rally. Khachanov understood that before the first ball was struck, and he never needed to raise his speed to prove it.

The second set was the real story. Blockx held his serve, dragged the set to 5-5, and for roughly forty minutes anyone watching could see why he had reached the quarterfinals. The turning point arrived in exactly the shape Khachanov had been waiting for: a rally that stretched past seven contacts. The longer it went, the more the left leg had to work. Khachanov broke in the penultimate game, held his own serve, and closed it 7-5.

In the third set the score stopped at 3-2, and that was the final point of the match. Khachanov had one break in hand, and that was the moment Blockx made the decision no player wants to make in a Grand Slam quarterfinal.

Collective memory tends to make one familiar mistake here. We remember the winner, and we compress everything else into a footnote. Khachanov's 2026 US Open semifinal has been mentioned repeatedly this week. The names of those who walked off mid-match in quarterfinals have largely vanished from the summaries. A young player who reached a Grand Slam quarterfinal can end up remembered by an asterisk.

There is another, more counter-intuitive reading. People say a player who reaches a semifinal because an opponent retired has been handed a rest. In tennis, the opposite is closer to the truth. A match that stops in the third set is not a light training session. It is a contest cut off at the moment rhythm was building, leaving a player to walk into a semifinal without the sensation of closure. Tennis is one of the few sports where the clock is not the referee. No whistle, no time limit, only the body and the score. When the body speaks, the match ends on its own terms.

People tell me I do not understand elite tennis, but I understand what it does not say. What it does not say lives in the medical report, in the morning before a match when a player tests a staircase and immediately knows the answer, in the decision not to compete that nobody is ever trained to make.

Ahead of him, Khachanov will face the winner between top seed Alexander Zverev and Botic Van De Zandschulp, with the semifinal scheduled for Friday. The other half of the draw is an all-American meeting between No. 8 seed Ben Shelton and No. 11 seed Frances Tiafoe, the first semifinal at America's biggest hard-court event in years that requires no translation of identity.

Khachanov walks into that match with three years of waiting behind him and a quarterfinal that ended before it truly ended. Victory is not the only thing worth recording. What remains open is whether a player can carry the rhythm of two and a half abandoned sets into a Grand Slam semifinal.