It was a good day for Americans at the US Open as Madison Keys and Coco Vandeweghe moved into the quarter-finals, while world number one Karolina Pliskova also progressed.

Keys and Vandeweghe upstaged Elina Svitolina and Lucie Safarova respectively to join Venus Williams and Sloane Stephens in the last eight as four Americans secured a spot in the US Open quarters for the first time since 2002.

Pliskova moved a step closer to retaining her top ranking after blitzing Jennifer Brady in New York on Monday, while Kaia Kanepi defeated Daria Kasatkina.

KEYS STUNS SVITOLINA

The American prevailed 7-6 (7-2) 1-6 6-4 against fourth seed Svitolina at Flushing Meadows.

Svitolina was in contention for the number one ranking and she looked set to stay in the hunt after claiming the break in the final set.

But Keys – through to her first US Open quarter-final – rallied to earn a meeting with Estonian qualifier Kanepi.

Former world number 15 Kanepi accounted for Kasatkina 6-4 6-4.

VANDEWEGHE BOLSTERS US CONTINGENT

The 20th seed secured her first US Open quarter-final berth courtesy of a 6-4 7-6 (7-2) victory against Safarova.

Somewhat of a grand slam specialist after reaching the semi-finals at the Australian Open and last eight at Wimbledon, Vandeweghe needed 100 minutes to see off the Czech.

Vandeweghe faces another Czech in the quarters – Pliskova.

"It's definitely the first strike kind of tennis, I think is the easiest way to simplify it," said Vandeweghe. "If I'm hitting my shots, I'm definitely doing a lot better job in the scoreline than she is and vice versa. So I think it's pretty much as simple as that."

PLISKOVA ROUTS BRADY

It was a convincing display from Pliskova, who dismantled Brady 6-1 6-0 on Arthur Ashe Stadium.

Pliskova was below her best against Nicole Gibbs in the second round, while she saved a match point in her win over Zhang Shuai last time out.

But Pliskova was back to her best in a 45-minute demolition.