Karolina Muchova overwhelmed Romania's Sorana Cirstea 6-0 6-3 on Tuesday to set up a US Open 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.
"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."