The all-American semifinal between Ben Shelton and Frances Tiafoe had already given the Arthur Ashe crowd plenty to react to. But things took another turn when the chair umpire appeared to make a harsh call at a crucial point in the match. The crowd was then left watching as Shelton walked over to the chair to question the decision.

The American walked to the chair umpire, Aurelie Tourte, and said, “Why did you not say something then? How you gonna pull it after and then not say, ‘Oh yeah?’ You gotta say something immediately.”

What made Shelton frustrated was not just the stoppage, but when Tourte called it. Tiafoe had advantage at deuce, leaving Shelton staring at another tense break-point moment once again. Then Shelton fired a rocket; Tiafoe answered with a casual backhand slice that floated long.

But before anyone could react, Tourte stopped play and explained Tiafoe had raised his hand.

That was enough for Shelton to walk straight toward the chair and question the call. Tourte said Tiafoe had said “sorry, sorry” before serving, so the point was replayed.

Shelton’s issue appeared to be the delay, because Tourte waited until the ball landed. With the crowd watching closely, Shelton kept his composure and eventually held serve under pressure.