Reigning WorldSBK Champion Jonathan Rea put in a late charge to top the opening WorldSBK free practice at a damp Motorland Aragon after Leon Camier had led by almost two seconds with ten minutes left to run.
The Castletown resident stuck in his customary fast opening two laps to set a 2'05.461 and then retired to the garage and await a drier track but it was Red Bull Honda's Camier who made the bets use of the wetter conditions, putting the new Magneti Marelli electronics to good use.
Camier upped his pace lap-on-lap to hit top spot with a 2'03.815 before going a tenth better and then, with 12 minutes left to run, the Andorra resident stuck in a 2'02.972 to go 1.8s clear of Rea's Kawasaki team-mate Tom Sykes.
Rea came back out with eight minutes to go and immediately launched himself back into the fray, going second with a 2'04.141 and then building to a 2'02.298 despite having a big moment through the mini-Corkscrew.
Marco Melandri, on the Aruba Ducati, also nipped ahead of Camier with a 2'02.889 for second while series rookie and reigning STK1000 champ Michael Ruben Rinaldo claimed fourth with a 2'03.132 with Pata Yamaha's Michael van der Mark in fifth.
Sykes slipped back to sixth place, one ahead of Loris Baz on the Althea BMW. Xavi Fores started brightly on the Barni Ducati and ended in eighth with Alex Lowes, and Lorenzo Savadori completing the top ten.
Title contender Chaz Davies had a quiet session in 11th place, just ahead of Tati Mercado and Jordi Torres. Milwaukee Aprilia new-boy Davide Giugliano took 17th place on his debut for the team while PJ Jacobsen was 19th.
