The Manxman was part of an eight-man break which went clear after 50 miles of the 114-mile race which featured four Sky riders.
For the first time in years, Sky's job was made more complicated - mostly thanks to the presence of the talented Yates brothers, riding for the Orica GreenEdge World Tour team - but Kennaugh and team manager Rod Ellingworth had faith in their squad.
"You can never be sure," said Ellingworth, "but I was fairly confident the guys had the race smarts to deal with them and we did have numbers. In the finale I told Ben [Swift] and Pete just to race to the finish; there were no team orders."
Kennaugh broke clear with his team-mate Swift and Simon Yates with 11 miles to go, but Kennaugh's incessant attacks cracked Yates and the Sky pair sprinted down Abergavenny High street to contest the win. "I'm not sure you can say I wanted it more than Ben, but I was really determined. If I had been a betting man I wouldn't have put money on me, but I knew it was a tricky sprint to judge from racing here before."
Kennaugh had been on the shortlist to start the Tour de France with Sky next weekend, but he did not make the final selection. "It's disappointing, but that's sport. They picked the strongest team to back Chris [Froome]," said Kennaugh who will now target the Tour of Spain.
In the women's race the Wiggle-Honda team found themselves in a similarly happy position, with three of their riders in the crucial eight-rider break which turned out to be a race-winning attack. In the final sprint, contested by four riders, Laura Trott was quickest. "It's such an amazing feeling. It's up there with winning a world championships for me," said Trott, who took both the elite and under-23 titles.
Scottish Commonwealth Games selection Katie Archibald, riding for her Pearl Izumi team, made it into the winning pack, but was dropped on the final climb, less than two miles from the line. "This is only the second road race I've done this year, I've been focused on track training," said Archibald, who won the silver medal in the under-23 rider competition within the main race.
"I did too much work near the finish. I was thinking I was pursuit training and every time I saw someone attack, I chased them down. I'll learn," said the 20-year-old, happy enough as the Games approach.