Former world number one Caroline Wozniacki and first-time Grand Slam semi-finalist Peng Shuai will meet for a place in the US Open title match after dominant victories on Tuesday.
Wozniacki, the runner-up at Flushing Meadows in 2009, dismissed 13th-seeded Italian Sara Errani 6-0, 6-1 and is back in the semi-finals of a major for the first time since the 2011 US Open.
China's Peng, in the quarter-finals of a major for the first time in her 37th attempt, made similarly short work of Swiss teen Belinda Bencic 6-2, 6-1.
Peng joined two-time Grand Slam champion Li Na and Zheng Jie as the only Chinese to reach the last four of a Grand Slam.
"Thirty-seven times Grand Slam," Peng said, then had to stop the thought as she struggled to contain her emotions after taking apart Bencic in just 64 minutes.
"It's a little bit too exciting," she said. "I love tennis, I love to play, but it's a long time, the career. It's tough. Sometimes I've thought to give up and stop playing because I don't know if I can make it or not.
"My coach and my parents always told me to fight and not give up - that today was coming."
Wozniacki was similarly convincing on a windy night on Arthur Ashe Stadium court, where towels from the players' chairs and stray plastic bags had to be corraled.
In a match between two players with an uncanny ability to extend rallies, Wozniacki's 26 outright winners to the 12 of Errani made the difference.
Errani, who boasts a top-speed serve of less than 144.84 Km/h could not hold once in six service games.
She was unable to capitalise on any of four break points in the opening game of the match and after fighting for that hold, Wozniacki was rolling.