Kawasaki's Loris Baz took his first World Superbike win by overcoming the increasingly more treacherous conditions at the Silverstone Circuit north of London.
The first attempt to start the race ended on the first lap with crashes by pole-sitter Liberty Racing Team Effenbert Ducati's Jakub Smrz and Team Effenbert Liberty Racing Ducati's Maxime Berger, along with David Johnson (Team Pedercini Kawasaki) and Norino Brignola (Grillini Progea BMW). Smrz and Berger made the re-start, Johnson and Brignola didn't.
The race was declared wet at the start, forcing riders to make tire choices they hoped would be suitable at the end. Of the 23 starters, 20 chose Pirelli's Diablo B mid-soft slick, with one on a rear intermediate and two on full rains. Three riders chose intermediate fronts and two were on rain fronts.
There was no rain at the start, with conditions remaining mostly constant for the first 12 of 18 laps, though rain was first reported around lap eight. When the rain picked up the lap times soared. Baz's best lap was a 2:07.895 on lap 10, but by lap 14 he was at 2:22.628 and sandwiched among a host of local heroes; BMW's Leon Haslam and FIXI Crescent Suzuki's Leon Camier were first and second, respectively, and Kawasaki's Tom Sykes was fourth.
Two laps later Haslam was still leading, but now his lap time was over 2:42, Ayrton Badovini was up to second, from ninth on lap 14, Baz was third and Camier had crashed out at Becketts.
As the riders started the final lap BMW Motorrad Italia GoldBet's Michel Fabrizio was in the lead, from fifth the previous lap, with Honda World Superbike's Johnathan Rea up to second from sixth. Baz was third, Badovini fourth, and Althea Racing Ducati's Carlos Checa fifth, the top five covered by .788 of a second.
The final lap was a wild one with ghe 19-year-old Baz taking the lead from Fabrizio in Stowe Corner and sprinting to victory by .383 of a second. Badovini was third and Rea fourth, the top four within .539 of a second of each other.
Checa was half a second back in fifth with 1.6 seconds on Haslam.
Haslam's teammate Marco Melandri was a distant seventh, three seconds up on Sykes.
The battle for ninth went to Althea Racing Ducati's Davide Giugliano over Aprilia's Eugene Laverty by .065 of a second.
FIXI Crescent Suzuki's John Hopkins retired with a technical problem on the 11th lap.
The race was so unpredictable that the order of the top three changed each of the final 10 laps.
Aprilia's Max Biaggi crashed out of sixth on the final lap, though he maintained his championship lead. Biaggi has 271.5 points to 259.5 for Melandri, with Sykes a distant third at 220.5.
World Superbike Race One Results:
1. Loris Baz (Kawasaki)
2. Michel Fabrizio (BMW)
3. Ayrton Badovini (BMW)
4. Johnathan Rea (Honda)
5. Carlos Checa (Ducati)
6. Leon Haslam (BMW)
7. Marco Melandri (BMW)
8. Tom Sykes (Kawasaki)
9. Davide Giugliano (Ducati)
10. Eugene Laverty (Aprilia)