Melbourne: Defending champion Stan Wawrinka wasted five match points before sealing a straight sets win over Japanese fifth seed Kei Nishikori to reach the semi-finals at the Australian Open on Wednesday.

The Swiss fourth seed won 6-3, 6-4, 7-6 (8/6) in just over two hours and will now face either top seed Novak Djokovic or eighth seed Milos Raonic for a place in Sunday's final. Nishikori had mastered the Swiss over five sets in the quarter-finals at last year's US Open, but it was a far different outcome this time.