Reigning MCE British Superbike champion Tommy Hill made a late charge to grab the fastest lap in miserable conditions during the first free practice session at Oulton Park.
The Swan Yamaha rider knocked Tyco Suzuki's Josh Brookes off the top spot with his final lap in the wet at the Cheshire circuit, where FP1 was delayed by more than an hour due to heavy rain and surface water on the track.
Hill's fastest lap of 1m 49.347s put him 0.213s ahead of the Australian rider, with wet weather expert Alastair Seeley third quickest, despite crashing out unhurt at Druids as the session reached a conclusion on the second Tyco Suzuki.
A number of track inspections were carried out before the riders finally ventured onto the track this morning.
Alex Lowes posted the fastest time early in the 50-minute session on his WFR Honda before Brookes edged his way to the front.
However, Scott Smart on the Moto Rapido Ducati made a surprise move to the top of the times with a lap in 1m 50.174s before he was overhauled by Hill, Brookes and Seeley in the closing stages, eventually ending FP1 in an impressive fourth.
The top six was completed by Shane Byrne on the Rapid Solicitors Kawasaki ZX-10R ahead of initial pacesetter Lowes.
Samsung Honda's Michael Laverty, a winner at Snetterton and Knockhill, went seventh fastest – almost 1.5s behind Hill – with Gary Mason eighth on the Pr1mo Bournemouth Kawasaki.
Mason is standing in this weekend for the injured James Hillier.
The top ten on the leaderboard was completed by Tommy Bridewell and Hill's Swan Yamaha team-mate Noriyuki Haga.
A number of riders fells at Shell Hairpin in the tricky conditions including Tristan Palmer, Florian Marino and Patric Muff.
Palmer and Muff escaped unhurt, while Marino was taken to the medical centre.
Jon Kirkham was also a faller, but walked away after his crash at Knickerbrook.
to view the full qualifying times