Nishikori eases into Geneva Open quarters

Kei Nishikori is trying to get some late claycourt form together ahead of the French Open.

Kei Nishikori is trying to get some late claycourt form together ahead of the French Open. (AAP)

Second-seeded Kei Nishikori of Japan eased into the Geneva Open quarter-finals, beating Mikhail Kukushkin of Kazakhstan 6-4 6-3 on Tuesday.

World No.9 Nishikori took a wildcard entry after a wrist injury affected his claycourt season and did not drop serve against the 88th-ranked Kukushkin.

Nishikori clinched the second-round match with a well-placed forehand from the baseline.

Also Tuesday, fifth-seeded Steve Johnson of the United States advanced to the second round, winning 6-3 6-3 against Frenchman Stephane Robert.

Janko Tipsarevic of Serbia, another wildcard, beat ninth-seeded American Ryan Harrison 6-4 7-6 (7-5) in a first-round match.

With a second-round match against top-seeded Stan Wawrinka as the prize, Rogerio Dutra Silva of Brazil beat Portugal's Joao Sousa 6-4 7-6 (7-5).

Wawrinka is the defending champion at his home tournament.