Proudly resplendent in the colours of the South African national road race champion, the Mitchelton-Scott rider kicked into top gear with 200 metres to go, after enjoying some time on teammate Adam Yates's wheel in the final kilometre.
It was then a straightforward gallop to the finish in Saint-Just-Saint-Rambert, first down the centre and then on the left with Julian Alaphilippe (Quick-Step Floors) and Pascal Ackermann (BORA-hansgrohe) left to fight for the minor placings. Yellow jersey Michal Kwiatkowski (Sky) also had a dig for the in, but finished behind Tiesj Benoot (Lotto Soudal) for fifth.
It was yet another win in a purple patch month for the Mitchelton-Scott outfit after various triumphs across its men's and women's teams.
But it was a victory that surprised the South African after a rough day in the saddle.
"It was a tough day all day, I actually didn't feel too good," he said. "I actually told (Alex) Edmondson he should go for the win himself and then I said if I'm there, in the end, I'll try but don't look after me.
"So I surprised myself actually and in the end, I found myself in a good position and then decided to go at 200 metres. It was a long way out but I had good legs in the final. I had no plan actually even in the team meeting I thought it was a bit far fetched I didn't know how I was going.
"To beat guys like Kwiatkowski and Alaphilippe just before the Tour de France and to win at the Dauphine, I'm really chuffed."
Brice Feillu (Fortuneo Samsic), Lawson Craddock (EF Cannondale Drapac), and Nicolas Edet (Cofidis) broke away early after the start of the 179km stage in Valence, and were soon fighting it out for the first KOM points atop the category two Col de Leyrisse which Feillu claimed.
The trio reached a maximum advantage of around six minutes with 123 kilometres to the finish, as they duelled over the remaining six categorised climbs, Feillu narrowly beating Edet to the KOM jersey by one total point.
With the puncheur and sprint trains sharing the load at the front of the bunch from around 80 kilometres to go, the leaders' advantage plummeted until they finally gave up the ghost 12 kilometres from the finish.
The race continues with another lumpy 180km stage from Montbrison to Belleville en Beaujolais with the five categorised climbs probably not arduous enough for the sprinters/puncheurs to stay away from a bunch finish.
Stage two will be streamed here and broadcast on SBS Viceland from 11:15pm AEST.