Kei Nishikori keeps on winning in Australia

Japan's Kei Nishikori reached the fourth round at the Australian Open with a straight-sets victory over Russia's Evgeny Donskoy on Friday.

Nishikori completed a 7-6 (7/3), 6-2, 6-3 victory in 2hr 6min on Show Court Two to get to the last 16.

The world number 18, who had a medical timeout for strapping treatment to a left ankle, will next face either Spanish fourth seed David Ferrer or Cypriot 28th seed Marcos Baghdatis in Sunday's fourth round.

Nishikori has enjoyed strong form in Australia, reaching the Brisbane semis before retiring hurt and making the Australian Open quarter-finals last year, the best ever Grand Slam performance by a Japanese man.

Nishikori only dropped his service once, while breaking the Russian's serve four times. He made more errors than winners (33 to 29)

"I think I played well in the important games. It wasn't easy to play today with the wind," Nishikori said.

"But like in the last couple games I played really well and have more confidence coming to play. I think I'm in good shape."

Nishikori is the last Japanese player in the men's singles draw after the exits of Go Soeda and Tatsuma Ito, while 42-year-old Kimiko Date-Krumm plays her third-round match against unseeded Serb Bojana Jovanovski on Saturday.

"It's good for Japanese tennis, for sure and I'm very happy that Kimiko is doing well," he said. "That's amazing how much she can play."