MELBOURNE (Reuters) - Defending champion Stan Wawrinka avenged his US Open quarter-final defeat to Kei Nishikori in style with an emphatic 6-3 6-4 7-6(6) victory to charge into the semi-finals of the Australian Open on Wednesday.

The fourth-seeded Swiss has worked his way slowly into the year's first grand slam but put his foot to the floor at a sun-drenched Rod Laver Arena, dominating Nishikori with raw power and compiling an exhaustive highlight reel of cleanly struck winners.

Wawrinka's backhand was particularly deadly, picking off the clean-hitting Japanese from all points of the court, but the Swiss was also impressive rushing to the net, a relatively new weapon in his arsenal.

Wawrinka made hard work of the tiebreak, blowing five match points after storming to a 6-1 lead, but closed it out on the sixth with an ace to set up a semi-final with the winner of top seed Novak Djokovic and Milos Raonic.