Is therre anything that Serena Williams cannot do?
Tennis' greatest superstar moves a match closer to history and a record 23rd Grand Slam victory.
She met her toughest test yet head on defeating Simona Halep 6-2, 4-6, 6-3 on Wednesday night to reach the semifinals.
Halep, seeded No. 5 and the runner up in the 2014 French Open became the first player to break Williams' serve and the first to win a set off the tournament's No. 1 seed.
But after going 0 for 12 on break points in the second set, Williams righted herself, broke on her first opportunity of the third to go ahead 3-1, and was on her way. She finished with 18 aces.
Williams is bidding for her seventh title at Flushing Meadows and 23rd overall at a major tournament, which both would be records for the Open era, which dates to 1968.
Last year in the semifinals, Williams' attempt to finish off a calendar-year Grand Slam ended with an upset loss to unseeded Roberta Vinci.
Her opponent Thursday will be 10th-seeded Karolina Pliskova of the Czech Republic, who beat the 34-year-old American's older sister Venus in the fourth round.