It’s the first win for the No. 31 Daytona Prototype, which moved under the Action Express umbrella this year after a lackluster 2014 season. It was also the fifth different Prototype winner in five races this season in the Tudor United Sportscar Championship.

It was almost an Action Express one-two in Detroit, but Joao Barbosa, who shares the No. 5 Corvette DP with polesitter Christian Fittipaldi, spun on the very last lap as hard rain began to fall, and the No. 60 Michael Shank Racing with Curb-Agajanian Honda-powered Ligier JS P2 of John Pew and Oswaldo Negri got by for second. Barbosa recovered for third. Finishing fourth were Joey Hand and Scott Pruett in the No. 01 Chip Ganassi Racing with Felix Sabates Ford EcoBoost Riley.

“It was good hard racing all the way through,” said Cameron, who has seven victories, but none in the Prototype class until today. The on-and-off rain, which really began to fall at the end of the race, made the track unpredictable. “One corner would be wet,” Cameron said, “and then the next time we’d come through, it would be dry. We had no idea what to expect.”

In fact, four GT Daytona cars piled into the tire barrier just past the checkered flag, when the rain was falling hardest. Jan Heylen, driver of the No. 58 Wright Motorsports Brumos Porsche 911 GT America, was treated in the infield care center, as was one track worker. Another track worker was taken to the hospital. No further information was available.

Next up for the TUDOR United SportsCar Championship is the Sahlen’s Six Hours of the Glen at Watkins Glen International, on June 26-28.