— Serena Williams already was struggling to keep up in a fast-paced US Open semifinal when she stopped behind the baseline after a third-set point and leaned over. She held that pose for a bit, then clutched at her lower left leg and asked for a trainer.

While Williams took a medical timeout for a tape job for what she later said was an Achilles issue — her latest bid for a 24th Grand Slam singles title seemingly slipping away — her opponent, Victoria Azarenka, sat in a sideline seat, eyes closed, calm and composed as can be.

After a delay of about five minutes at Arthur Ashe Stadium, action resumed, and while Williams raised the force of her shots and volume of her shouts, it was Azarenka who finished off a 1-6, 6-3, 6-3 victory Thursday to return to a major championship final for the first time in seven years.

In Saturday’s final, Azarenka will face Naomi Osaka in a meeting between two-time major champions who have both been ranked No. 1 in the past and have been by far the two best players since tennis resumed last month after a pandemic-forced hiatus.

After going a full calendar year without a single tour-level victory, Azarenka has won 11 matches in a row. Osaka’s streak is at 10 after her 7-6 (1), 3-6, 6-3 win over Jennifer Brady in a hard-hitting semifinal filled with fast serves and strong forehands.