Japanese star Kei Nishikori is into the third round of the Australian Open with a straight-sets win over American Austin Krajicek.

The No.7 seed eclipsed his long-time friend and training partner 6-3 7-6 (7-5) 6-3 on Wednesday.

Nishikori’s best result at Melbourne Park is the quarter-finals, which he reached in 2012.

He will next face the winner of the clash between German qualifier Daniel Brands and Spanish 26th seed Guillermo Garcia-Lopez.