Ahead of that clash, which came in the semifinals in 2016, Williams was the overwhelming favourite, but Pliskova came out firing and won through to her first Grand Slam final 6-2 7-6. He was agonizingly close to getting there past year at the U.S. Open, leading by two sets against Juan Martin del Potro in the round of 16 before the 2009 champion roared back to win.
Rafael Nadal is back in the U.S. Open quarterfinals after beating Nikoloz Basilashvili 6-3, 6-3, 6-7 (6), 6-4. "I was just happy to get through it to be honest", Williams said.
She next meets Karolina Pliskova in the quarter finals. In the Instagram world (it does) but, in the real world, it takes a while for your body to come back.
All the publicity campaigns in the world could not help Serena Williams as she flirted with an abrupt exit from the US Open.
But she couldn't convert two break chances in the 10th, and after Williams saved two set points Kanepi knotted the match with a service victor on her third set point.
Serena equalled her most-lopsided victory against her sister with a 6-1, 6-2 rout in the third round of the United States (US) Open.
So what if it happened to be her big sister?
So much has been riding on Williams doing well at this tournament, not least the multi-million dollar advertising splurges built around the women's game's most bankable star, who is very much the face of this Open. It was a crucial moment and the 36-year-old quickly gained an advantage that she never threatened to lose. Williams leads the ace race with 47, Pliskova is tied in second place with Madison Keys with 26.
The Ukrainian said: "I was really dizzy and I asked nature or God or somebody, "please move the shade over faster".
"I know she was the best at that time, but I just wanted to win".
Pliskova and Williams, who will kick off the evening session, have split their two career meetings, with the Czech having won their most recent battle in the 2016 U.S. Open semi-finals.
Kanepi is ranked only 44th, but she's been a top-20 player in the past and has made it to Grand Slam quarterfinals a halfdozen times.
"I don't really feel pressure, because I'm on this journey of getting back to where I was", she said. I'm feeling great now, too.
American Stephens continues her defence on Tuesday against Latvia's 19th seed Anastasija Sevastova, which begins under the midday sun on Arthur Ashe. "There is always a chance for me". "I hope to be ready to make that happen".