Posted on September 8, 2026
NEW YORK: Karen Khachanov has spent much of the 2026 season searching for the kind of tennis that once made him a regular threat deep into Grand Slams.
He found something even more valuable on Monday night at the US Open: the ability to survive when his best tennis was no longer enough.
Khachanov recovered from two sets to one down to defeat No. 14 seed Learner Tien 7-5, 4-6, 6-7(6), 6-1, 6-4 in a gripping five-set fourth-round contest at Louis Armstrong Stadium, reaching the US Open quarterfinals for only the second time in his career.
The 30-year-old now faces Belgian breakthrough star Alexander Blockx for a place in the semifinals.
The result adds another major twist to a men’s tournament that has steadily lost established contenders. Readers following the changing championship picture can find all of The Sports Encounter’s latest reporting through our Tennis Hub.
Khachanov vs Tien: US Open 2026 Result at a Glance
| Match Detail | Karen Khachanov | Learner Tien |
|---|---|---|
| Round | US Open 2026 Round of 16 | |
| Final score | 7-5, 4-6, 6-7(6), 6-1, 6-4 | Lost in five sets |
| Seed | Unseeded | No. 14 |
| Ranking entering tournament | World No. 50 | World No. 15 |
| Aces | 9 | 8 |
| Break points converted | 8 of 11 | 5 of 14 |
| First-serve points won | 74% | 69% |
| Next opponent | Alexander Blockx | Eliminated |
Full point-by-point and statistical information is available through the official US Open SlamTracker.
Khachanov Takes the First Set, but Tien Refuses to Let the Match Settle
The opening set immediately suggested that this would be very different from Khachanov’s first three matches in New York.
He had entered the fourth round having dropped only one set during victories over Roman Andres Burruchaga, Felix Auger-Aliassime and Benjamin Bonzi. His four-set win over Auger-Aliassime had already become one of the biggest results of the tournament, a performance we examined in our US Open report on Khachanov’s upset of the No. 3 seed.
Tien posed a completely different problem.
The 20-year-old left-hander brought speed, court coverage and an ability to change the rhythm of rallies rather than trying to overpower Khachanov from the same positions.
Khachanov eventually took a tight first set 7-5, but there was little indication that he had established control over the match.
Tien confirmed that in the second.
The American responded with a 6-4 set to level the contest, forcing Khachanov to solve a matchup that was becoming increasingly uncomfortable as the afternoon turned into evening at Louis Armstrong Stadium.
Tien Wins the Third-Set Tiebreak and Moves One Set From the Quarterfinals
The third set became the emotional center of the match.
Neither player managed to create enough separation during the first 12 games, sending the set into a tiebreak with the entire match beginning to feel balanced on a handful of points.
Tien won that battle 8-6.
Suddenly, the American led two sets to one and stood one set away from matching the Australian Open quarterfinal run he produced earlier this season.
For Khachanov, the situation had reversed completely.
He had started the match as the more experienced Grand Slam competitor and had won the opening set. Two sets later, he was facing elimination against a player 10 years younger who had already survived his own five-set test against Jakub Mensik in the previous round.
Tien’s run had already become part of a rapidly changing men’s tournament. The Sports Encounter’s analysis of the US Open quarterfinal race highlighted how opportunities were opening across a draw that had lost several established names.
Khachanov was now in danger of becoming the next one.
The Fourth Set Changed the Match Completely
Khachanov’s response was emphatic.
He won the fourth set 6-1.
The importance of that scoreline went beyond forcing a fifth set. After losing two consecutive sets and being pushed through a tense tiebreak, Khachanov regained control quickly enough to prevent Tien from carrying the momentum of the third set into the finish.
That reset mattered.
Khachanov’s game has always been built around first-strike power. His serve creates opportunities, while the weight of his groundstrokes can shorten points when he is able to establish position near the baseline.
Tien had repeatedly made him work through longer patterns and uncomfortable changes of direction. The fourth set gave Khachanov the scoreboard freedom he needed to play more decisively.
By the time he completed the 6-1 set, the match had effectively started again.
One set remained.
Khachanov Holds His Nerve in the Fifth
The fifth set asked a different question.
Khachanov no longer needed to rediscover momentum. He needed to finish.
Tien had already demonstrated his comfort in long matches by beating Mensik in five sets two nights earlier. He had also spent much of this season proving that his age does not prevent him from competing with established players on major stages.
Khachanov therefore had little reason to expect the American to disappear simply because the fourth set had gone badly.
The deciding set remained competitive, but Khachanov finally created enough separation to take it 6-4 and complete one of his most important Grand Slam victories in years.
The celebration represented more than relief.
Khachanov is back in a US Open quarterfinal.
The Break-Point Numbers Explain Why Khachanov Survived
The match statistics reveal an important difference between the two players.
| Key Statistic | Karen Khachanov | Learner Tien |
|---|---|---|
| Aces | 9 | 8 |
| Double faults | 7 | 8 |
| First serve in | 66% | 64% |
| First-serve points won | 74% | 69% |
| Break points converted | 8 of 11 (73%) | 5 of 14 (36%) |
| Service games won | 79% | 68% |
Tien actually created more break-point opportunities.
He earned 14 compared with Khachanov’s 11.
The difference came in execution.
Khachanov converted eight of his 11 opportunities. Tien converted five of 14.
In a five-set match containing several momentum shifts, that efficiency became decisive. Tien repeatedly created opportunities to place greater pressure on Khachanov’s serve, but Khachanov escaped enough of them to stay alive before taking far greater advantage when the American’s serve came under pressure.
Khachanov also won 74% of his first-serve points, five percentage points more than Tien.
The serving numbers were hardly dominant by Khachanov’s standards, but they were strong enough when combined with his superior break-point conversion.
Khachanov’s US Open Revival Has Become One of the Stories of the Men’s Draw
There was little evidence before the tournament that Khachanov was about to produce this run.
He entered New York ranked No. 50 and unseeded at a Grand Slam for the first time in eight years. Outside the majors, he had struggled to build sustained momentum through much of 2026.
The contrast with his career record is striking.
Khachanov has reached the quarterfinals at every Grand Slam. He made the US Open semifinals in 2022 and followed that with an Australian Open semifinal in 2023. He has also won an ATP Masters 1000 title and previously reached a career-high ranking of No. 8.
Before this tournament moved into its decisive stages, Khachanov spoke about trying to reconnect with that standard.
“This is the next step, the next goal.”
That comment, made during an official US Open feature on Khachanov’s understated Grand Slam résumé, now feels considerably more significant.
He has reached that next step.
The question is whether he can go further.
Khachanov Has Rebuilt His Tournament One Round at a Time
His path through New York has become progressively more demanding.
| Round | Opponent | Result |
|---|---|---|
| Round 1 | Roman Andres Burruchaga | 6-3, 6-0, 6-1 |
| Round 2 | Felix Auger-Aliassime | 6-7(5), 6-3, 6-2, 6-2 |
| Round 3 | Benjamin Bonzi | 6-3, 6-2, 6-4 |
| Round of 16 | Learner Tien | 7-5, 4-6, 6-7(6), 6-1, 6-4 |
The victory over Auger-Aliassime first changed the perception of his tournament.
Our subsequent analysis of the evolving US Open men’s draw identified Khachanov as one of the experienced players capable of taking advantage of the seeds disappearing around him.
That possibility has now become reality.
He has won four matches in New York and beaten the No. 3 and No. 14 seeds along the way.
Learner Tien Leaves New York With His Reputation Enhanced
The defeat will hurt Tien because of how close he came.
He led two sets to one and stood within a set of his first US Open quarterfinal.
His tournament should still strengthen the broader argument that he belongs among the most significant young players in men’s tennis.
Tien began the event by defeating Nuno Borges in straight sets. He then beat Gael Monfils in what became the Frenchman’s final Grand Slam singles match before surviving Mensik in five sets.
Khachanov therefore became the fourth different test of Tien’s New York run.
Power.
Experience.
Five-set pressure.
A hostile scoreboard after taking a two-sets-to-one lead.
Tien ultimately lost, but his performance gave the crowd at Louis Armstrong another glimpse of why he has risen so quickly.
The larger emergence of younger players has been one of the defining themes of this year’s tournament, something already visible when rain, upsets and early exits began reshaping the US Open during the opening rounds.
Alexander Blockx Is Waiting in the Quarterfinals
Khachanov’s reward is a meeting with another 21-year-old breakthrough player.
Alexander Blockx defeated Francisco Cerundolo 6-3, 4-6, 7-5, 7-5 earlier Monday to reach the first Grand Slam quarterfinal of his career.
According to the official US Open match report, Blockx became the first Belgian man to reach a US Open singles quarterfinal.
His run is particularly remarkable because this is his first US Open main draw.
He has already eliminated No. 5 seed Flavio Cobolli and No. 24 Francisco Cerundolo, two results that remove any possibility of Khachanov treating the quarterfinal as a favorable draw simply because Blockx lacks Grand Slam experience.
The matchup creates another generational contrast.
Khachanov brings more than a decade of professional experience, two previous major semifinals and the knowledge of what a US Open quarterfinal feels like.
Blockx brings momentum, freedom and the confidence of a player who has already exceeded his previous Grand Slam achievements.
What Khachanov’s Victory Means for the US Open Men’s Title Race
The wider significance extends beyond one quarterfinal.
The tournament began with Jannik Sinner absent through injury and Carlos Alcaraz returning from a long wrist layoff. Novak Djokovic then disappeared in the first round. Taylor Fritz, Felix Auger-Aliassime, Alex de Minaur, Daniil Medvedev and several other established contenders followed.
The Sports Encounter had already identified the unusual level of uncertainty before the tournament in our pre-tournament analysis of the men’s title race.
The draw has become even less predictable since.
Our original US Open draw analysis described paths that have since been transformed by injuries and upsets.
Khachanov now belongs among the players who have benefited from that upheaval while also contributing directly to it.
He eliminated Auger-Aliassime himself.
Now he has removed Tien.
Elsewhere in the draw, Ben Shelton has reached a blockbuster quarterfinal with defending champion Carlos Alcaraz after producing one of his cleanest matches of the tournament against Stefanos Tsitsipas, a matchup analyzed in our Shelton vs Alcaraz quarterfinal report.
New York has reached the stage where every remaining match carries championship consequences.
The Sports Encounter Verdict
Karen Khachanov did not reach the US Open quarterfinals because Monday’s match was comfortable.
He reached it because the match became uncomfortable and he found a way through it.
Tien changed the rhythm after losing the opening set. He won the second, survived the third-set tiebreak and moved within one set of eliminating another experienced opponent.
Khachanov then responded with his most important stretch of tennis of the match, taking the fourth set 6-1 before completing the job 6-4 in the fifth.
The result reconnects him with the stage where some of his best Grand Slam tennis has been played.
Four years after reaching the semifinals in New York, Khachanov is back in the last eight.
The path ahead remains dangerous.
So does he.
For the broader tournament schedule, contenders and championship context, see The Sports Encounter’s complete US Open 2026 guide.
Frequently Asked Questions
Who won Karen Khachanov vs Learner Tien at the 2026 US Open?
Karen Khachanov defeated Learner Tien in five sets in the fourth round of the 2026 US Open.
What was the final score of Khachanov vs Tien?
Khachanov won 7-5, 4-6, 6-7(6), 6-1, 6-4.
Did Karen Khachanov come back from behind against Learner Tien?
Yes. Tien led two sets to one after winning the third-set tiebreak 8-6. Khachanov responded by winning the fourth set 6-1 and the deciding fifth set 6-4.
Who will Karen Khachanov play in the US Open quarterfinals?
Khachanov will face No. 28 seed Alexander Blockx of Belgium, who defeated Francisco Cerundolo 6-3, 4-6, 7-5, 7-5 in the fourth round.
Has Karen Khachanov reached the US Open quarterfinals before?
Yes. Khachanov reached the US Open semifinals in 2022. His 2026 run marks the second time he has reached the quarterfinal stage in New York.
What is Karen Khachanov’s best Grand Slam result?
Khachanov has reached two Grand Slam semifinals: the 2022 US Open and the 2023 Australian Open. He has also reached at least the quarterfinals at all four Grand Slam tournaments during his career.
Was Learner Tien seeded at the 2026 US Open?
Yes. Tien was the No. 14 seed and entered the tournament ranked No. 15 in the world.
How important were break points in Khachanov’s victory?
They were one of the clearest statistical differences. Khachanov converted eight of 11 break-point opportunities, while Tien converted five of 14.
Who did Khachanov beat before facing Tien?
Khachanov defeated Roman Andres Burruchaga in the first round, No. 3 seed Felix Auger-Aliassime in the second round and Benjamin Bonzi in the third round before beating Tien.
How far had Learner Tien previously gone at the US Open?
The 2026 fourth round represented Tien’s deepest US Open run to date. He had already demonstrated his Grand Slam potential by reaching the Australian Open quarterfinals earlier in 2026.