It took more than three hours of play before a tired Karolina Pliskova could happily clasp her hands in a victory gesture, having secured a US Open tennis quarter-final spot against her Belarusian opponent.

7–5, 6–7, 6–2 were finally the final scores against the Belarusian Victoria Azarenka.

- The match was even, there were long ball duels, says Pliskova from the court, and says she is satisfied with how the serve works and how she moves across the court.

The 30-year-old Czech is ranked 22nd in the world and has reached the final in a grand slam context on two occasions, the US Open in 2016 and Wimbledon last year, where in both cases there were losses to Angelique Kerber and Ash Barty respectively.

Despite being world number one, Pliskova has usually not had to carry the title of favourite.

- I've had so many ups and downs in my career, so I'm used to everything, says the Czech.

In the quarter-finals, she meets Belarusian world number five Aryna Sabalenka, who knocked out home hope Danielle Collins 3–6, 6–3, 6–2.

The two have dueled against each other in the same arena three times in the last four years, and Collins must continue to chase a victory.

- She played incredible tennis.

It was a crazy level today.

I'm super happy with the win, she's tough to face, says Sabalenka from the field.