Kawasaki's Tom Sykes has sent out the first warning shot to his rivals after emerging top of the timesheets during the opening day of the free testing at Phillip Island.

The Briton was one of 18 riders taking to the Australian circuit for the first of three 'unofficial' testing days, the Kawasaki rider posting a best of 1min 33.0secs to head up his main rivals.

Though early wet conditions and cool weather kept the lap record of 1min 30.882s well out of reach, Sykes's performance is an early indication that Kawasaki's shake-up over the winter, which saw Paul Bird Motorsport replaced by the Provec team, has been a beneficial one.

Once rounded, Sykes's best time was matched reigning champion Carlos Checa who proved the addition of 6kg to his Althea Ducati over the winter hasn't hampered his pace around one of his most successful hunting grounds.

It was also a good start to the week for the factory Aprilia and BMW teams, with Eugene Laverty landing in third position, ahead of former Yamaha counterpart Marco Melandri, while their respective team-mates Max Biaggi and Leon Haslam followed up in fifth and sixth.

Effenbert-Liberty Ducati occupied seventh, eighth and tenth in the order of Jakub Smrz, Sylvain Guintoli and Maxime Berger, with Joan Lascorz splitting the trio in ninth.

Leon Camier brought his Crescent Fixi Suzuki up to 12th, but it was an otherwise disappointing day for the team after John Hopkins crashed on his first lap and was taken to hospital where it was confirmed he has broken a bone in his hand.

Elsewhere, it was also a tough day for the WSBK rookies, with Davide Giugliano and Lorenzo Zanetti bringing up the rear in 16th and 17th, behind Phillip Island wild-card David Johnson on the Rossair AEP BMW.

Among those choosing not to participate in the three-day test are Honda's Jonathan Rea and Hiroshi Aoyama, Red Devil Ducati's Niccolo Canepa, ParkinGO Aprilia's Chaz Davies, Grillini BMW's Mark Aitchison and Pro Ride Honda's Raffaele de Rosa.

The sextet are expected to be present for the official Infront test at Phillip Island next week in the run up to the opening round.