Alvaro Bautista put Suzuki on top of the timesheets during a soaking wet Friday afternoon practice session for the MotoGP season finale at Valencia.
Only eleventh fastest in the wet morning session, Bautista lapped one-second slower due to worsening weather in the afternoon. But others lost more time and Bautista kept his GSV-R on top by 0.341sec over Ducati's Nicky Hayden.
Hayden had led an all-Ducati top four halfway through the 45-minute session, with Pramac's Randy de Puniet also taking a turn at the top on his way to an eventual third place 0.7sec from Bautista.
Rookie Karel Abraham had been among the leading Desmosedicis, but finished in fourth place after a heavy accident at turn one at the end of the session.
Yamaha's Ben Spies had suffered an near identical fall during the midway stages and although able to walk away the American, who has missed the last two races after falling hard at Phillip Island, didn't return to the track.
Abraham's rookie of the year rival Cal Crutchlow briefly topped the session on his way to fifth place for Monster Yamaha Tech 3, with outgoing Repsol Honda rider Andrea Dovizioso the top RC212V in sixth.
Fellow Italian Valentino Rossi was seventh, ahead of 2011 world champion Casey Stoner and team-mate Dani Pedrosa. Stoner and Pedrosa had led a Repsol Honda one-two in the damp morning session, when the fastest laps of the day were set.
Josh Hayes, the reigning double AMA Superbike champion who has been drafted in at Tech 3 to replace the injured Colin Edwards, completed an impressive opening day in tenth place (+3.3sec).
Fellow replacement Katsuyuki Nakasuga - again substituting for 2010 world champion Jorge Lorenzo at the factory Yamaha team - also moved forwards, finishing one place behind Hayes in eleventh this afternoon.
Loris Capirossi - who will end a 22-year grand prix carer on Sunday - was twelfth this afternoon on the #58 Pramac Ducati, a tribute to Marco Simoncelli. Simoncelli's Honda Gresini team-mate Hiroshi Aoyama was another to fall heavily, on his way to 15th.
Friday practice 2:
3. de Puniet