Josh Cook, Ash Sutton and Mikey Doble each won at Croft during a BTCC weekend in which penalties repeatedly influenced the final order.
Cook secured the rain-affected opener for Speedworks Corolla Racing. Tom Ingram passed him on the road late in the race, but a five-second track-limits penalty left Cook the winner, Sutton second and Ingram third.
Sutton then won race two after an opening-lap move around Cook at Tower. It was his fifty-fifth BTCC victory, moving him above Gordon Shedden to fifth on the championship's all-time winners list.
Doble took the finale in his Power Maxed Racing Audi, earning his third career victory. The weekend also brought setbacks for Sutton's principal championship rivals, limiting their opportunity to reduce his advantage.
With Silverstone next, Croft strengthened Sutton's position while showing how track-limits enforcement could change the outcome even after close battles had been settled on circuit.