Stan Wawrinka carves up Kei Nishikori to reach semi-finals

Defending champion Stan Wawrinka avenged his U.S. 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.

"I'm still nervous even after the end of the tiebreak," Wawrinka said.

"There is no easy match even from the first round. I am playing well and I'm happy to be back playing the semi-final."

It was the 29-year-old Swiss' first win over a top-five player since he beat Roger Federer in Monte Carlo last year and the workmanlike victory undoubtedly sent a warning to four-times champion Novak Djokovic he would need to be at his best to reclaim the Australian Open title.