King led home the championship leader Tom Golding (Assetto Motorsport), who kept up the pressure throughout the 20-minute race to come home second at the flag, just over a second in arrears.
While that duo were out on their own for much of the race, a thrilling battle raged for third, eventually resolved in favour of W2R’s Rob Keogh.
He’d initially run third until ceding the position to his team-mate Jack Oliphant on lap four, but Oliphant then lost places to both Keogh and SVG’s Alistair Barclay on the final lap, coming home fifth behind them.