Williams will face 20-year-old Naomi Osaka in Saturday's final.
Serena Williams fell behind 0-2 in her U.S. Open semifinal to Anastasija Sevastova, a lethargic start that disappointed an Arthur Ashe crowd eager to support the 23-time major champion.
She righted the ship. Quickly.
Williams went on to win 12 of the final 13 games in dominant fashion, winning 6-3, 6-0 to reach the U.S. Open final for the ninth time. She is a six-time winner of the event.
After missing a year to give birth to her daughter Alexis Olympia—and suffering from serious post-pregnancy health concerns—Williams, seeded 17th in New York and ranked 26th in the world, has now reached the final of the last two majors.
"I'm just beginning you guys, this has only been a few months," Williams told an overjoyed crowd in her on-court interview after the match. "I'm really looking forward to the rest of the year, and next year. I'm really looking forward to the possibilities. This is just the beginning."
She lost 6-3, 6-3 to Angelique Kerber in July's Wimbledon final but will be looking for a different result this time around. A win would go down as one of sports' greatest comeback stories, and it would also see Williams tie Margaret Court's all-time record of 24 Grand Slam singles titles, though 13 of Court's titles were won before the Open Era.
At nearly 37 years old, Williams would also become the oldest woman to win a singles major title.
Williams will face 20-year-old Naomi Osaka, who is the first Japanese woman to reach a Slam final in the Open Era, in Saturday's final. Osaka defeated Madison Keys 6-2, 6-4 in the second semifinal on Thursday night.