Serena Williams said she had cleared a major hurdle in her comeback after beating Karolina Pliskova 6-4, 6-3 to reach her 13th US Open semi-final.
Until this victory over the world No8, Williams had lost all three of her matches against top-10 opponents since starting her return in March after a 14-month break to have her first child.
Williams said it was “shocking” that this was her first win over a top-10 player since she beat Johanna Konta at last year’s Australian Open.
Describing it as “a really big step” in her comeback, Williams said her defeats earlier this year against her sister Venus, Angelique Kerber and Petra Kvitova had been down to a lack of matches. “I’m getting those matches now,” she said.
“Now I feel like I’m at a level where I can play and try to compete against the top 10.”
Williams said that every match meant a lot to her. “I don’t think I have another 10 years of having opportunities to be able to play and win championships,” she said.
Pliskova led 4-2 in the first set before Williams won eight games in a row with a barrage of big shots. On her 100th appearance in Arthur Ashe Stadium, she secured her 94th victory at Flushing Meadows by holding serve to love with three aces and a smash.
In Thursday’s semi-finals, Williams will face Latvia’s Anastasija Sevastova, who secured a place in the last four of a Grand Slam event for the first time by beating Sloane Stephens, the defending champion, 6-2, 6-3.
The defeats of Pliskova and Stephens, who had been suffering from a sinus problem, mean that the top-10 seeds have all been knocked out, as they were in the early stages at Wimbledon.