Davies started their Ford Mustang Boss 302 in eighth but stormed to third on the opening lap of the contest for Group 1 Saloon Cars of a type raced between 1970 and 1982.
He then overtook the Chevrolet Camaro of fast-starting James Thorpe at the end of Lavant Straight on lap three to follow the similar Mustang of Timo Bernhard.
The two Mustangs stopped for the driver changes together and Sutton emerged ahead of Fred Shepherd, in for Bernhard.
Sutton looked set to have the race under control until a safety car was called with 24 of the 45 minutes to go, with the Ford Capri of Nick Jarvis/Mike Rockenfeller stranded at the end of the pitlane.
Sutton bolted at the restart with 15 minutes to go as the other frontrunners made their way through traffic.
Once Shepherd made it into second, the two leaders exchanged fastest laps. Shepherd kept the pressure up but Sutton always looked in control on his way to victory by 2.6 seconds.
“Thank you to Craig Davies for letting me have a go in ‘the beast’, as we call it,” said Sutton. “Craig did a mega job to come up from eighth on the grid. I just had to bring it home.”
Triple British Touring Car champion Gordon Shedden found himself in fifth after the pitstops in the Camaro Jack Young had kept in sixth during the early stages. Shedden dived past the Camaro of triple World Touring Car champion Andy Priaulx on the St Mary’s right-hander and immediately set fastest lap as he chased Dario Franchitti for third.
The two Scots were soon together and, with just under five minutes left, Shedden repeated his St Mary’s move to complete the podium. Franchitti, driving the Chevy started by James Cottingham, narrowly held on to fourth from Priaulx, in Thorpe’s Camaro.
The Camaro of Marino Franchitti/Oliver Bryant meant American V8s filled the top six places.
Tom Ingram was best of the rest in the Rover SD1 started by Mike Whitaker Jr, but the 2022 BTCC champion only held off the charging Ford Capri of Jake Hill by 0.182s. The BMW West Surrey Racing star took the restart 13th in the car that Ric Wood had in 10th before the stops but charged through to head the Capri horde.
