Serena Williams survived a third-round scare at the US Open to topple 2017 champion Sloane Stephens 2-6 6-2 6-2 and keep alive her bid for a record-equalling 24th Grand Slam title.
A sure-footed Stephens pounced early as third seed Williams struggled with her first serve and committed 13 unforced errors in the first set, claiming an early break for a 2-1 lead.
The 26th seed kept Williams on the run as she saved two break points, with the 38-year-old struggling to find her rhythm.
But the momentum dramatically shifted in Williams' favour in the second set. The third seed opened a 4-2 lead as she cleaned up her game and kept psyching herself up in the absence of the legions of fans who usually flock to Flushing Meadows.
The stands are empty this year due to the novel coronavirus pandemic.
Williams, who got just half of her first serves in during the first set, appeared increasingly confident as the match went on, dropping just one first-serve point in the third set as the contest slipped through Stephens' fingers.
Williams next faces Greek Maria Sakkari, who beat her in the third round of the Western & Southern Open just 10 days ago.
"It was intense, I have to say," Williams, chasing a seventh title at the New York major, said in an on-court interview. "It always brings out the best in my fitness when I play Sloane."
She sent down a dozen aces including one on her second serve.
"My thing is just try to stay calm and be more serene," Williams, a notorious perfectionist, told reporters. "I just knew it was important for me just to keep trying, just to keep going."
Williams played the match in front of her daughter, three-year-old Olympia, and said she hoped "that she saw her momma fighting."
"I don't think she was paying attention, between you and me," she added. "She may have been playing with some princesses upstairs."