Click here for full WorldSBK FP1 results from Misano
Italy's Davide Giugliano put the Aruba.it Ducati on top at Misano during the first free practice session to head the World Superbike times from American Nicky Hayden in San Marino.
Kawasaki's Tom Sykes, who had held sway on the ZX-10R for much of FP1, finished third fastest.
Giugliano's time of 1m 35.460s left him 0.175s clear of Hayden (Honda World Superbike Team), while Yorkshireman Sykes was two tenths of a second back on the early pacesetter at the Marco Simoncelli Circuit.
Welshman Chaz Davies and team-mate Giugliano were fast out of the blocks as they took turns to set the pace at the beginning of the session, although Sykes was soon into his stride as he moved to the top of the time sheets.
Barni Racing's Xavi Forés led briefly before Sykes assumed control again, only to be bumped down the order when Giugliano posted his fastest overall lap, with Hayden also producing a quick time to slot into second place, only 0.027s ahead of Sykes.
Forés finished fourth on his Ducati Panigale, 0.349s behind Giugliano, while reigning champion Jonathan Rea was fifth fastest on the second of the factory Kawasaki machines ahead of Althea BMW's Markus Reiterberger.
Davies dropped down the standings to seventh on the Aruba.it Ducati, almost six tenths behind team-mate Giugliano, while Alex Lowes was eighth on the Pata Yamaha R1 as he continues to work towards regaining full fitness in the wake of his spill in the second race at Sepang.
The top ten was completed by Michael van der Mark (Honda World Superbike Team) and Lorenzo Savadori on the Ioda Racing Aprilia.
Niccolo Canepa, filling in for the injured Sylvain Guintoli in the Pata Yamaha team, was 15th fastest.