Second seed Dominic Thiem bulldozed Australia’s Alex de Minaur in straight sets Wednesday to reach the US Open semi-finals.

The Austrian defeated the 21st seed 6-1, 6-2, 6-4 in just 2 hours 4 minutes inside Arthur Ashe Stadium and he will play third-seeded Russian Daniil Medvedev in the last four for a place in Sunday’s final.

“I had a great feeling from the first moment on,” said Thiem, gunning for his first Grand Slam title at Flushing Meadows.

“My feeling was that first set, especially until I broke him for the second time, was really intense, very long rallies.

“The first and second set second I guess it looks way easier on the scoresheet than it was actually,” he added.

The 27-year-old Thiem hit 11 aces compared to just one by the 21-year-old de Minaur.

Thiem won a whopping 83 percent of first serve points, while de Minaur, playing in his first Grand Slam quarter-final, could only manage 49 percent.

Thiem was able to withstand most of what de Minaur threw at him, getting 81 percent of returns in.

The powerful Austrian also smashed 44 winners while De Minaur mustered only 17.

Medvedev wins

Third seed Daniil Medvedev defeated Russian compatriot and childhood friend Andrey Rublev in straight sets to reach the semi-finals.

Medvedev overcame his 10th-seeded opponent 7-6 (8/6), 6-3, 7-6 (7/5) in 2hr 27min inside Arthur Ashe Stadium.

Rublev raced to a 5-1 lead in the first-set tie-break before Medvedev, last year’s US Open runner-up, hauled back to win it 8-6 with an ace.

“In these moments you feel like you have to fight for every point, but you’re also thinking, ‘Okay, I have probably lost this set,’” said Medvedev.

“I felt like I could get in trouble so I was really happy to get the winner in this tough tie-breaker.

“One point decided two sets so it was a really tough match and Andrey was playing unbelievable actually,” Medvedev added.

In what was a baseline slugfest for much of the match, big-hitting Medvedev smashed 16 aces and won 89 percent of first-serve points.

His defensive game was also superior, making 75 percent of returns to just 54 percent by Rublev.

The disqualification of Novak Djokovic for accidentally hitting a line official with a ball during the last 16 means the US Open will crown a first-time Grand Slam winner this year.

Fifth seed Alexander Zverev of Germany faces Spain’s 20th seed Pablo Carreno Busta in the competition’s other semi-final.

The men’s semi-finals take place on Friday.