NEW YORK — American Jessica Pegula knocked world number one Iga Swiatek out of the US Open 6-2, 6-4 on Wednesday to reach her first Grand Slam semifinal.

The sixth seed threw her hands into the air after closing out the biggest win of her career in front of the elated home crowd at Arthur Ashe Stadium in her seventh major quarterfinal.

Swiatek, who withdrew from last month’s Canadian Open citing fatigue, appeared out of sorts from the start as she struggled with her serve and helped her opponent with 41 unforced errors.

The Pole had not been broken since the first round of the tournament but dropped serve with a double fault in the opening game and again in the third.

Pegula looked in cruise control in the second set as she broke Swiatek again in the third game.

Pegula led 40-0 in the final game but needed the encouragement of the home crowd to get her over the line as Swiatek produced a pair of fine winners to stay in it. — Reuters