BMW rider Sykes continued his strong Monday form by setting the second-fastest time behind Bautista, ending up only 0.213s adrift, while reigning British Superbike champion Leon Haslam improved to third, another tenth back, on the best of the Kawasakis.
Four-time champion Jonathan Rea was fourth-fastest in the second session and fifth overall behind Melandri, 0.419s shy of ex-MotoGP rider Bautista.
Puccetti Kawasaki rider Toprak Razgatlioglu completed the combined top six followed by a trio of Yamaha riders, with Michael van der Mark leading Sandro Cortese and Alex Lowes, who suffered two crashes during the day, first at Turn 1 and later at Turn 4.
Jordi Torres brought a fourth Kawasaki into the top 10 on the satellite Pedercini machine.
Honda once again had a low-key day, with Leon Camier and Ryuichi Kiyonari concluding the Phillip Island test in 13th and 15th places respectively, split by the second factory Ducati of Chaz Davies.
Eugene Laverty (GoEleven Ducati)’s day was brought to a premature halt by technical problems, while Alessandro Delbianco (Althea Honda) likewise didn’t run in the afternoon after a crash in the morning.