Grand Slam winner Marin Cilic's preparation for the Australian Open got off to the perfect start Wednesday with an easy victory in the last 16 of the ATP Maharashtra Open.

The world number six breezed into the quarter finals of the $550,000 tournament, held in the Indian city of Pune, with a straight-sets win over local wildcard Ramkumar Ramanathan.

Cilic, the 2014 US Open champion and number one seed in Pune, won 6-4, 6-3.

It was the Croatian's first match of the hard-court event after he received a bye in the opening round.

Cilic will take on Frenchman Pierre-Hugues Herbert, ranked 81st in the world, in Thursday's last-eight tie.

South African number two seed Kevin Anderson also won his last-16 match after Thiago Monteiro of Brazil retired hurt in the second set.

Fourth seed Benoit Paire beat Hungary's Marton Fucsovics but it was a miserable day for defending champion and third seed Roberto Bautista Agut.

The Spaniard, 20th in the ATP standings, was dumped out of the competition 6-3, 7-6 (7/5) by France's Gilles Simon, ranked a lowly 89th.

Agut claimed the title last year when it was known as the Chennai Open.

The Australian Open, the first Grand Slam of the year, starts on January 15.