Local hope Alex de Minaur has suffered a thumping straight-sets Australian Open quarter-final loss to world No.1 and defending champion Jannik Sinner.

A night that promised so much for Alex de Minaur ended with another trip back to the drawing board following a loss that will require some serious soul-searching.

Defending champion Jannik Sinner dismissed eighth seed Alex de Minaur 6-3 6-2 6-1 to reach the Australian Open semi-finals and extend the country's decades-long wait for another homegrown singles winner at the Grand Slam on Wednesday.