Greece's Stefanos Tsitsipas celebrates winning his quarter-final against Italy's Jannik Sinner

Melbourne (AFP) - Stefanos Tsitsipas stormed into his third Australian Open semi-final with a blistering straight-sets victory over Jannik Sinner on Wednesday.

The Greek fourth seed played his best tennis yet in the year’s opening major to romp past the 11th-seeded Italian 6-3, 6-4, 6-2 in 2hr 6min and into a semi-final against either Daniil Medvedev or Felix Auger-Aliassime.

It was a most impressive performance from the world number four who grasped control of the quarter-final on Rod Laver Arena with a break in Sinner’s opening service game and did not relinquish his firm grip.

“My humility helped a lot today, I knew I was going out on the court to face a very good player,” Tsitsipas said.

“I just focused on my very best shots and it paid off better than I thought.

“Stepping on the court and having the crowd support is truly unbelievable.”

Not even a rain interruption which forced the stadium roof to be closed and change match conditions early in the second set stopped the Tsitsipas momentum.

“It’s part of the game. I knew I was heading in the right direction,” Tsitsipas said.

“The conditions might have changed a bit but so did my mind. I tried to adapt. It just worked.”

Last year’s French Open finalist regained his timing and hit the ball majestically, reeling off 30 winners – 17 on his forehand – and breaking Sinner’s serve four times.

There was a delay while the roof was closed and rain mopped up on Rod Laver Arena

Sinner, rated one of the hottest young talents on the men’s circuit, did not get a break point in any of Tsitsipas’s 14 service games and was blown away.

Tsitsipas broke immediately when the Italian overhit a forehand and served out strongly to take the opening set in 36 minutes.

The Greek grabbed another break in the third game of the second set before rain stopped play and forced the stadium roof to be closed with more threatening weather forecast.

He was relentless and powered his way to a double break in the third set which gave Sinner no way out.

Tsitsipas has reached the semi-finals twice before in Melbourne and became the first Greek player to reach a major final when he lost to Novak Djokovic in last year’s French Open.

Sinner was bidding to join compatriot Matteo Berrettini in the semi-finals.