Kei Nishikori started the first Grand Slam of 2016 with a straight-sets win over Philipp Kohlschreiber in Melbourne on Monday.
The seven-seeded Nishikori was solid on serve throughout the match, giving up no break points in the 6-4, 6-3, 6-3 Australian Open first-round win.
"My serve was good, but my opponent was very tough," said Nishikori. "He should have been seeded, and so that's why I had to concentrate."