Pune - World number six Marin Cilic progressed without dropping a set at the ATP Maharashtra Open Thursday as he gears up for the first Grand Slam of 2018 later this month.

The Croatian despatched Frenchman Pierre-Hugues Herbert 6-3, 6-2 to move with ease into the semi-finals of the $550,000 tournament, held in the western Indian city of Pune.

Cilic, the 2014 US Open Champion, smashed seven aces as he won the quarter-final match in just over an hour.

The top seed is yet to drop a set in the hard-court event as he warms up for the year's opening Slam, the Australian Open, which starts in Melbourne on January 15.

Cilic will play Gilles Simon, 89th in the world rankings, in Pune's semi-finals after the Frenchman overcame Spaniard Ricardo Ojeda Lara 6-2, 6-3.