Click here for full BSB FP1 results from Donington Park
Christian Iddon has gone quickest in a soaking wet opening free practice at Donington Park as the top three in the Showdown Leon Haslam, Shane Byrne and Jason O'Halloran all slipped off.
The Tyco BMW rider set the top time in damp conditions before a heavy rain shower set in drenching the Donington Park track which curtailed any quick running.
With the weather forecast predicting dry conditions for the rest of the weekend the majority of the grid opted against extensive running on the wet tyres but it didn't stop a handful of riders slipping off in the rain including the top three.
Honda's Jason O'Halloran fell unhurt at McLeans and shortly after Shane Byrne suffered the same fate on his Be Wiser Ducati at Coppice corner. Joining the fallers was BSB championship leader Leon Haslam who crashed at the Melbourne hairpin but was able to recover his JG Speedfit Kawasaki and return to the pits.
With the top three in the championship battle falling James Ellison looked to profit by finishing the session second fastest ahead of Bennetts Suzuki's Tommy Bridewell and former team-mate Ryuichi Kiyonari who is enjoying his second outing with Smiths BMW.
Alastair Seeley grabbed fifth on the timesheet for RAF Reserves BMW ahead of O'Halloran despite his early fall with Josh Hook placing his Team WD-40 Kawasaki seventh. Byrne claimed eighth ahead Jakub Smrz as Haslam rounded out the top ten runners.