Karolina Pliskova won her 10th match in a row to take a victory lap into the semi-finals of the US Open 6-2, 6-2 over teenaged Ana Konjuh on Wednesday.
The Czech tenth seed, who claimed the Cincinnati title last month, was untroubled in the contest, losing just five points on serve.
The winner finished with back-to-back aces after 18-year-old Croatian Konjuh double-faulted to end the penultimate game.
Pliskova, who upset Venus Williams in the fourth round, won her 31st match of the season.
"It's an amazing feeling, I'm so excited to be in my first grand slam semi-final," Pliskova said. "I played a good match today, I know Ana can do better.
"I'm very happy with this win."
Pliskova, noted for a big delivery, said that her serve made the difference. "Breaking in the first game also helped me. I was calm and going for my shots.
"Ana and I play the same game, so I had to do well."