Ashleigh Barty and CoCo Vandeweghe saved two championship points to shock Australian Open champions Timea Babos and Kristina Mladenovic and each win their first Grand Slam title at the US Open.
Six-time champion Serena Williams claimed 12 of the final 13 games en route to a straight-set victory over Anastasija Sevastova and a trip to her 31st Grand Slam championship match at the 2018 US Open.
20-year-old Naomi Osaka moved into the biggest final of her career, fending off last year's finalist Madison Keys to reach the championship match of the 2018 US Open.
Serena Williams needed three sets to maneuver past powerful Kaia Kanepi and make the 15th US Open quarterfinal showing of her illustrious career.
Defending champion Sloane Stephens surged into the quarterfinals, avenging a Western & Southern Open loss to Elise Mertens to make it into the last eight for a second straight year at the US Open.
2016 US Open finalist Karolina Pliskova previewed her upcoming quarterfinal clash with 23-time Grand Slam champion Serena Williams, whom she beat in their last encounter at this tournament two years ago.
WTA Insider breaks down the 2018 US Open draw, where three pre-tournament favorites all landed in the top half of the draw.