Serena Williams survived a first-set scare against compatriot Sloane Stephens to move into the US Open fourth round, 2-6, 6-2, 6-2. The 23-time Grand Slam champion began slowly and sluggishly, and the 2017 winner outhit and outran her. But Williams improved her serving massively in the second set, increasing the percentage of points won on her first serve. And her daughter Olympia was looking on as she won the decider, breaking the Stephens serve to 15 in the final game. "I forgot she was coming out! I hope she saw her momma fighting…I don't think she was paying attention!" Serena laughed afterwards. Turning her analysis to the match, she said: "It was intense, I have to say. We always have some really incredible matches, and it brings out the best in my fitness when I play Sloane."