A rampaging Madison Keys has completed an American sweep of the US Open women's quarter-finals to guarantee a homegrown champion at the year's final grand slam.
Keys' 6-3 6-3 victory over Estonia's Kaia Kanepi ensured Americans grabbed all of the semi-finals berths at Flushing Meadows for the first time since Tracy Austin, Chris Evert, Martina Navratilova and Barbara Potter filled the final four spots in 1981.
Stephens advanced with a gritty victory over 16th seeded Anastasija Sevastova which was followed by 37-year-old Venus Williams outlasting 13th seed Petra Kvitova.
CoCo Vandeweghe shocked world number one Karolina Pliskova, before Keys produced a ruthless thumping of Kanepi to reach her first grand slam semi-final since the 2015 Australian Open.
Her victory means Spain's Garbine Muguruza overtakes Pliskova as the number one ranked woman in world tennis.
It has been a sensational run by the 22-year-old Wandeweghe, who missed the opening two months of the season recovering from left-wrist surgery and the U.S. Open is just her 10th event this year.
Keys needed just 69 minutes to see off a weary opponent who appeared to be simply out of gas after playing eight matches, including three in qualifying to get into the main draw.
Keys will now face Vandeweghe for a spot in Saturday's final while Williams will meet Stephens.