Coco Gauff won at 4:43 p.m., and Arthur Ashe started emptying almost immediately. Her match was only the second of Session 21, with Karen Khachanov and Alexander Blockx still scheduled third on the same ticket. Yet by their 5:15 start, large sections of Ashe were empty. Fans had access to another Grand Slam quarterfinal and still chose to leave once Gauff was done. Blockx retired shortly before 7 p.m., and less than an hour later, the stadium was filling again for the separate Zverev night session. Did fans come for the tennis, or just the stars?

Well, for starters, Karen Khachanov vs. Alexander Blockx was reportedly played in front of a visibly sparse Arthur Ashe crowd. Tennis journalist Ben Rothenberg pointed it out on X: “Ashe is so yawningly empty for an early evening quarterfinal that they’re inviting fans from the upper decks to fill the lower bowl for Blockx-Khachanov. But wow, sure, men’s tennis doesn’t need any tweaks, it’s perfect as is, who could ever dare to suggest otherwise.”

And that is where the matchup itself becomes impossible to ignore.

Gauff is not just another player on the draw. She is an American Grand Slam champion with roughly 2.4 million Instagram followers and one of the biggest commercial profiles in tennis. Forbes estimated her 2026 off-court earnings at $28 million, backed by more than a dozen sponsors. Khachanov, despite being a former top-10 player and Grand Slam semifinalist, has roughly 338,000 Instagram followers. Then there is Blockx, whose profile was still catching up with his breakthrough. Recent estimates placed his Instagram following at only around 21,000 before this US Open run.

Put that commercial gap into a 23,000-seat stadium, with Khachanov-Blockx scheduled third immediately after Gauff, and the empty seats become easier to understand.

And fans had already seen this pecking order play out. After Gauff’s fourth-round win, ESPN stayed with her interview while Learner Tien was still fighting Khachanov in a live fifth set.

Viewers ripped the call as “clueless,” and the criticism was hard to miss. A live five-set Grand Slam battle was happening, yet Gauff still got the screen time. At that point, the message felt pretty clear: star power was winning over the tennis itself.

The scheduling only made that gap more obvious. Khachanov-Blockx was the third match of a day session that had started at 11:30 a.m., meaning some spectators had already spent more than five hours inside Ashe before the men took the court. Unlike Zverev’s later quarterfinal, they had no fresh ticketed audience coming in. That crowd belonged to the separate night session.

Arthur Ashe itself did them no favors either. The stadium holds more than 23,000 fans, compared with roughly 14,000 at Louis Armstrong. A crowd that might have looked respectable on a smaller court suddenly looked thin on tennis’ biggest stage.

And with no American player, no established rivalry, and Blockx eventually struggling physically, the match had little help keeping casual fans in their seats. What happened on court only made that problem worse.

Karen Khachanov advances as Alexander Blockx’s body gives out

Gauff-Andreeva gave Arthur Ashe plenty of drama. Gauff dropped the opening set 2-6, then survived two match points in a tense second-set tiebreak before taking it 9-7. From there, she took control, winning the decider 6-2 to complete a 2-6, 7-6(7), 6-2 comeback in two hours and 19 minutes.

The win sent her into her first US Open semifinal since her 2023 title run and marked her second straight Grand Slam final-four appearance.

Gauff later said Frances Tiafoe’s comeback the previous night had been on her mind.

“At the end of the first set I was thinking about Frances and how he came back yesterday,” Gauff said. “Honestly, I was just trying to leave the court with no regrets.”

The crowd fed off that comeback. Former British No. 1 Annabel Croft even described Gauff as almost “unrecognizable” from the player who had started the match.

Then Gauff left, and so did much of the atmosphere.

Khachanov quickly took control against Blockx, winning the opening two sets 6-2, 7-5. But the Belgian was already dealing with physical issues from his previous match and needed treatment again.

After Khachanov broke for 3-2 in the third, Blockx stopped.

“I think my body just gave up,” he admitted afterward.

Khachanov said the situation made the match difficult to enjoy fully because he could see Blockx struggling physically.

“He was suffering all over his body,” Khachanov said.

The retirement sent Khachanov into his third Grand Slam semifinal and second at the US Open, where he will face Alexander Zverev for a place in the final.

For Blockx, it was a painful end to a breakthrough run. The 21-year-old became the first Belgian man to reach a US Open quarterfinal and recorded the biggest win of his career against World No. 6 Flavio Cobolli.

But the bigger talking point was happening in the stands.

With upper-deck spectators reportedly being invited down to fill the lower bowl, the contrast with Gauff-Andreeva was hard to miss. Arthur Ashe can still feel like the biggest stage in tennis when the stars are there. The question is whether the US Open can make it feel that way when they are not.