New York: Karolina Pliskova said it was harder to beat Venus Williams than it was to stun Serena Williams to make the US Open final on Thursday.
The 10th seeded Czech clinched a famous 6-2, 7-6 (7/5) semi-final win to reach her first Grand Slam final, ending Serena's hopes of winning a record 23rd major and knocking the American off the top of the world rankings as a result.
The 24-year-old Pliskova also became just the fourth player to beat both the Williams sisters at the same Slam, after Justine Henin, Kim Clijsters and Martina Hingis.
But she believes she laid the foundations for her shock semi-final victory by saving a match point in her gruelling three-set win over Venus in the fourth round.
"To beat Serena, she's world No 1, so it's always tough to beat someone like this. She's never giving up. Even if she's losing, not playing her best, it's always tough to beat girls like this," said Pliskova. "But I would say it was a little bit tougher to play Venus because obviously I was a match point down and she was serving much better than Serena was tonight."
"Even my game I think was a little bit better against Venus. Everyone is gonna say it's amazing win tonight. But both matches were very good," she added.
Pliskova, the first Czech woman in the US Open final since Helena Sukova in 1994, will face new world number one Angelique Kerber, who beat Caroline Wozniacki in the second semi-final.