British rider Tom Sykes was the quickest around the track in the opening practice session of the World Superbikes event at Phillip Island on Friday.

In a hard-fought 60-minute session, nine other rides finished within the 1:31.543 that Sykes powered his Kawasaki to on the Victorian track.

Sylvain Guintoli - the 2014 world champion - was 0.1sec behind on his Yamaha, followed by last year's title winner, Jonathan Rea, in third.

Australian Mick Jones was 15th on his Ducati, while fellow countryman Josh Brookes was 18th in the 24-man field on his BMW.

The riders will return to the track on Friday afternoon.