Live updates on the US Open 2024: Men's semifinals with Fritz in action against Tiafoe and Sinner from the USA

Aryna Sabalenka had experienced this before: standing under the lights in front of an American crowd, with a lead and feeling that lead start to slip away. Twelve months ago, she was leading 1-0 against Coco Gauff and won the first set 6-2. Gauff won the next two sets and the title.

Sabalenka found herself in a similar situation against Emma Navarro. She served for the match at 5-4, while the crowd that had almost silenced her finally roared down Arthur Ashe. This time, she made it to the tiebreak from 5-6 down and crossed the finish line.

Everything went according to plan for Karolina Muchova, who had just returned from wrist surgery. She defeated the American world number six Jessica Pegula and with 6-1, 2-0 and 30-40 on Pegula's serve, the Czech could reach a Grand Slam final.

That's not how tennis works. After hitting Pegula wide with a forehand, as she had done all evening, Muchova came to the net to hit the ball away. She had lost control of the ball and it fell wide. That was the decisive game, even though there were still 16 games to play. The narrow margins of a semi-final.