Karolina Pliskova rallied from a set down to beat fellow Czech and 20th seed Barbora Strycova 6-7 (5/7), 6-3, 6-2 and make the Australian Open quarter-finals.
World number one Rafael Nadal notched up his 50th win at the US Open on Monday to reach the quarter-finals for the seventh time.
Rafael Nadal and Roger Federer won their third round matches to move closer to a blockbuster semi-final clash at the US Open.
Switzerland's Federer will be seeking his 20th Grand Slam title and his sixth in New York.
Australia's Nick Kyrgios humbled new world number one Rafael Nadal 6-2, 7-5 to reach Cincinnati Masters semi-finals on Friday.
Five tennis players have a chance to grab the world No 1 ranking at this week's Cincinnati Open.
Roger Federer climbed to No 3 in the latest ATP singles rankings while Karolina Pliskova topped the WTA charts despite never having won a Major.
Karolina Pliskova became the firm Wimbledon favourite on Wednesday when compatriot and two-time champion Petra Kvitova was knocked out.
Novak Djokovic clinched his first title since January with a 6-3, 6-4 victory over Gael Monfils.
With the Fed Cup tie level at 2-2, US Open finalist Karolina Pliskova teamed up with Barbora Strycova to defeat French Open doubles champions Caroline Garcia and Kristina Mladenovic 7-5, 7-5 to prolong the Czech Republic's reign
Karolina Pliskova beat Kristina Mladenovic 6-3, 4-6, 16-14 in an epic rubber which lasted 12 minutes short of four hours as the Czechs, chasing a fifth title in six years, got off to a sensational start.
German tennis player Angelique Kerber won her second Grand Slam title when she defeated Czech Karolina Pliskova in the women's singles final at the US Open.
Czech Karolina Pliskova lost 6-3, 4-6, 6-4 to new World No.1 Angelique Kerber but came tantalisingly close to a maiden Grand Slam win when she led 3-1 with a break in the decider.
Angelique Kerber, who won the 2016 Australian Open, beat Karolina Pliskova in the women's singles US Open final for her second Grand Slam title of the year
Angelique Kerber won her second Grand Slam title by beating Karolina Pliskova in the women's singles US Open final. Catch US Open tennis highlights here
This will be Angelique Kerber's third appearance in a Grand Slam final while Karolina Pliskova will be playing in her maiden Major summit clash
Karolina Pliskova stunned top seed Serena Williams in the US Open women's singles semi-finals
Serena Williams, 34, said "some serious left knee problems" had affected her game -- as much mentally as physically after her US Open semi-final loss.