Kennaugh attacked inside the opening kilometres of the road race in Glasgow and built up a lead of over two minutes on the field. As the weather worsened and the field began to whittle down it looked as though the Tour of Austria winner could hold on for a famous victory. However after nine laps of racing he was reeled in.
Cavendish spent the day as the Isle of Man's director sportif and without race radios played an integral part in guiding Kennaugh along.
"It was a gutsy ride by Peter. I didn't imagine that it would happen after the meeting we had last night but it was a gutsy ride. I believe we could have won though if we'd ridden a bit different but it was a good showing for the Isle of Man," Cavendish told Cyclingnews.
"I'd rather he had gone back at the beginning when no one went with him in the beginning. After that he was going, and going long."
Kennaugh eventually finished eighth with his Team Sky teammate Geraint Thomas (Wales) winning the race.
Cavendish is currently recovering from a shoulder injury sustained at the Tour de France. He crashed out on stage one to Harrogate and hospital checks revealed ligament ruptures with an AC-joint dislocation. He was operated within days and is now back on his bike and training.
He has not pinpointed his exact date for a return but could ride the Tour de l'Ain.
"I'm okay thank you. The surgery went well and it was a good operation. The recovery is going alright and I'm back on my bike. I don't know about my form because this is the first time into August when I've not ridden the Tour de France so I don't know how I’'m going to be at this point."
Asked if he had a comeback race in mind: "Not really. Maybe I'll do Tour de l'Ain but it's only a week away."