The Excelr8 Motorsport Hyundai i30 N benefited from being one of those to pit at the end of the green-flag lap for wet-weather Goodyear tyres when rain made the going slippery.
Chilton was able to defeat Adam Morgan – the West Surrey Racing BMW 330e M Sport newcomer was another to pit at the same time – by 7.394 seconds as the rain increased, making it impossible for those on slick rubber.
The race began with first-race winner Dan Cammish keeping Tom Ingram at bay for the lead, but when Ricky Collard parked his Toyota on the track at McLeans with suspension damage that triggered the safety car, it gave those on grooved tyres even more of an advantage as they were able to close the gap to the stricken slicks runners in front.
Once the field was released again it took little time for Chilton and then Morgan to carve their ways to the front, and it was just a matter of time before those who had started on slicks eventually gave up the struggle and pitted.
As the race settled down, Chilton was leading Morgan and Scottish BTCC debutant Ronan Pearson, who had also pitted his Excelr8 Hyundai at the end of the green-flag lap.
In fourth spot was Nic Hamilton, with his brother Lewis watching on from the pit garage and with rain tyres he’d had fitted to his Team Hard Cupra Leon before the green-flag lap even began.
Hamilton soon fell victim to the Motorbase Ford of Sam Osborne and Stephen Jelley’s WSR BMW, but he was still leading the Independents class as the race went into its closing stages.
Source: Autosport