Second seed Aryna Sabalenka crushed Qinwen Zheng 6-1, 6-4 at the Arthur Ashe Stadium on Wednesday to reach her fifth straight grand slam semi-final and end the 23rd seed’s charmed run at the US Open.

Sabalenka, who will move top of the world rankings next week, pummelled her Chinese opponent with 17 winners and never faced a break point.

Zheng had never made it to a major quarter final and endured a miserable time against the Australian Open winner, as she was unable to get much power off her serve and the Belarusian forced her into 23 errors.

“I’m super happy with the win against her... super happy with the performance,” said Sabalenka, who lost in the semi-finals in her previous two US Open appearances.

“I’m going to do everything I can to stay until the end.”

Outstanding defence

Karolina Muchova of the Czech Republic overwhelmed Romania’s Sorana Cirstea 6-0, 6-3 to set up a semi-final against American Coco Gauff.

Muchova, seeded 10th, smacked 32 winners and played outstanding defence to see off the 33-year-old Cirstea at Arthur Ashe Stadium and reach her first US Open semi-final.

“Unbelievable. It’s a really sweet victory and this stadium, I mean, incredible,” Muchova said.

“Thank you to everyone who came and cheered.”

French Open finalist Muchova got off to a quick start and raced out to a 3-0 lead before fending off nine break points to win a marathon game and extend to 4-0.

A flustered Cirstea’s backhand then landed wide to put her opponent up 5-0 and Muchova completed the bagel the next game.

After an animated conversation with her coach during the break between sets, Cirstea held to start the second and broke for 2-0 when her charge to the net caused Muchova to miss a passing shot.

But Muchova broke right back, and again for a 4-3 lead she would not relinquish as her net play, precise lobs and pinpoint serving carried the day.

Cirstea missed a swinging volley to set up match point, which Muchova converted with a forehand winner to end the contest in just over an hour and a half.

Next up for Muchova is Gauff, who was a 6-0, 6-2 winner over Jelena Ostapenko earlier in the day.

The Czech said she knows she will be up against both the 19-year-old American and the home crowd on Friday.

“Obviously she’s an amazing player. She has the home crowd here,” she said.

“It’s going to be very tough but I want to enjoy this win and then I’ll try to put up a battle against Coco.”

‘Mental endurance’

Gauff on Tuesday became the first American teenager to reach the US Open semi-finals since Serena Williams in 2001 and credited her “mental endurance” for getting her one step closer to a first grand slam title.

Gauff arrived in New York having played plenty of tennis over the past month as she lifted the titles in Washington and Cincinnati while also reaching the quarter-finals in Montreal but she has not shown any signs of slowing down.

“I think doing well in those tournaments built my mental endurance.

“Always had the physical endurance but it built my mental endurance,” the sixth-seeded Gauff told reporters after the match.

“Right now I feel emotionally fresh, which I think was the problem in the past in grand slams, I would emotionally be drained.

“Obviously I’m physically fresh and emotionally fresh, and I think that just came from experience.”

The 19-year-old Gauff advanced to the semi-finals with a clinical 6-0, 6-2 win over Latvian 20th seed Jelena Ostapenko at Arthur Ashe Stadium to match her career-best winning streak of 10 consecutive matches.

Gauff looked very fresh against Ostapenko, who beat world No.1 and defending champion Iga Swiatek in the fourth round, and chased down every ball sent her way en route to taking the first frame in 20 minutes.

She wrapped up the match in 68 minutes to reach her first US Open semi-final.

“Today was the best match I’ve played, for sure. Even though it wasn’t how I like to play, against her it’s so hard to be the aggressor sometimes,” said Gauff.

“So I think that, like, the decision-making that I’m making is probably the best I’ve had, and I feel really confident in all my strokes.”

Gauff felt that she was benefiting from a new outlook on life that has helped her to cope with pressure.

Rather than focus on that unrelenting pressure, Gauff has finally allowed herself to enjoy each moment she has on court while not taking any of it for granted.