Karolina Pliskova, a grand slam underachiever, has taken a big step towards shedding that unwanted label by sweeping past Croatian teenager Ana Konjuh 6-2 6-2 to roar into the semi-finals of the US Open.

Pliskova arrived at Flushing Meadows as the only player ranked inside the top 20 yet to reach the fourth round at one of tennis’s four blue riband events but the 10th-seeded Czech made her trip to the semis look like nothing new as she overwhelmed 18-year-old Konjuh in 57 minutes on Wednesday.

“It’s an amazing feeling, I am so excited to be in my first semi-final especially in this tournament I very much love New York and hardcourt season,” said Pliskova, who will next face either world No.1 Serena Williams or Romanian fifth seed Simona Halep.

“I think I played a very good match today.

“I did a quick break in the first game which helped me and I was more calm then and going for my shots.”

It was a ruthless and dominating performance from Pliskova, who did not face a break point while surrendering only five points on her serve.

The big-hitting Czech, who has fired more aces this season than any other player, opened the match with a bang, breaking the unsteady teen on her opening two serves en route to a 4-0 lead.

Pliskova lost only one point on serve in the opening set as she swept past the reeling Croatian in 28 minutes.

Konjuh began to find some rhythm and confidence near the end of the first and start of the second but could not keep it going and again found herself down a break 3-2.

At that point there was no way back for the 92nd ranked Croatian as Pliskova steamrolled through four straight games finishing her opponent off with back-to-back aces.

“I wasn’t at my best level today for sure, but she was just too good,” said Konjuh.

“Her serve is just too good.”