Serena Williams put aside some early shakiness and an early deficit, turning things around with an eight-game run on her way to a 6-4, 6-3 victory over the No 8 seed, Karolina Pliskova, for a spot in the semi-finals.

Pliskova is a big server and hitter in her own right, someone who briefly spent time at world No1 and was the runner-up at the US Open in 2016, when she beat Williams in the semi-finals.

Sloane Stephens, defending US Open champion, falls to Anastasija Sevastova Read more

It took Williams a little while to get going on Tuesday, as she pursues a seventh US Open title, and 22 of her 30 unforced errors came in the first set against Pliskova. That sluggish start came in the heat and humidity that hampered John Isner in his quarter-final loss to Juan Martin del Potro on Tuesday afternoon, and Roger Federer in his fourth-round exit against John Millman a night earlier.

With her older sister, Venus the woman she beat in the third round in her guest box, Williams looked tight. Her timing was off. She put a backhand into the net to get broken to 2-1 at the outset. Then, down 3-1, she faced three break points; if Pliskova had won any, she would have led 4-1. But Pliskova did not manage to put any of Williams’ serves in play on those key points.

Soon after that, Williams went from trailing 4-2 to not only taking the first set but also leading 4-0 in the second. By the end, Williams compiled a 13-3 edge in aces, and 35-12 in total winners.

The 36-year-old American did not compete in New York a year ago, because she gave birth to her daughter during the tournament. This time, Williams’s semifinal opponent will be Anastasija Sevastova of Latvia, who surprisingly beat defending champion Sloane Stephens 6-2, 6-3 earlier on Tuesday.