World championship leader Marc Marquez set the fastest time in Friday's opening practice ahead of this weekend's Australian MotoGP at Phillip Island. The Spanish Honda rider posted a quickest lap of one minute 29.602 seconds on a dry track ahead of Sunday's race. Marquez, who leads the world championship by 11 points with three races left, had 0.093secs to spare over Frenchman Johann Zarco on a Yamaha in the first free practice. <strong>____________________</strong> <strong>Read more:</strong> <strong>____________________</strong> Marquez topped the session despite not putting on a softer rear tyre, as did many of his rivals in the field with the possibilty of rain forecast for the weekend. Australian Jack Miller, in his first MotoGP event back since breaking a leg during training, was third-quickest, just 0.122secs behind Marquez's time. Ducati's Andrea Dovizioso, who downed Marquez on the final lap to win last weekend's rain-soaked Japanese GP and is second in the world championship, was fourth fastest, 0.151secs down on Marquez. Spain's Maverick Vinales, on a Yamaha, was fifth-fastest ahead of Suzuki's Andrea Iannone. Six-time premier class Phillip Island winner Valentino Rossi on a Yamaha, trailed in 13th place, some 0.951secs behind Marquez.