Dutch rider Marianne Vos won her second La Course title with a stunning late surge up the final climb in Pau.
Australia's Amanda Spratt led by 10 seconds into the final kilometre of the 121km circuit and was alone when she started the sharp ramp with 450m to go.
But Vos burst away from the other chasers, sprinted past Spratt and was able to coast over the line, beating Leah Kirchmann by three seconds.
Three-time world champion Vos won the first edition of La Course in 2014.
"This means a lot - I won five years ago and to win now again on a different circuit is a very special feeling," she said.
La Course was set up by Tour de France organisers ASO in 2014 in response to lobbying by Le Tour Entier, a campaign group that was co-founded by Vos.
That inaugural race ended in a sprint finish on the Champs-Elysees in Paris, while this edition saw the women's peloton tackle five laps of the individual time-trial course that will be used for stage 13 of the men's Tour de France later on Friday.
Vos, who won four stages of the Giro Rosa this month, was the favourite for victory on a course that featured several short but steep climbs and delivered in style after her CCC-Liv team-mates worked hard to limit Spratt's advantage.
"I enjoyed that circuit, there was a lot of different possibilities," said Vos.
"I feel really good, I came with good motivation out of the Giro Rosa and La Course was good inspiration to go again."
After an early breakaway of 10 riders was reeled in with around 50km to go, two-time defending champion Annemiek van Vleuten and world champion Anna van der Breggen exchanged attacks to force an elite selection.
With little cohesion in the group, a large bunch of riders bridged across before Mitchelton-Scott rider Spratt kicked away, bringing four riders with her.
That group was caught entering the final lap but Spratt managed to stay away and built a lead of 30 seconds as team-mate Van Vleuten disrupted the chase.
Yet ultimately Spratt lost crucial time on the wide, flat roads approaching the finish and Vos timed her attack up the 17% gradient climb perfectly, continuing the impressive form this season that could see her win a fourth world road title in Yorkshire in September.
Canadian Kirchmann held on for second, with Denmark's Cecilie Uttrup Ludwig claiming third.
Britain's Lizzie Deignan, who had not raced since winning the Women's Tour last month and is building her season around the world championships, sustained two mechanical problems and missed the split, finishing 77th and over 11 minutes down.
Deignan criticised the lack of progress in expanding La Course, which ran as a two-day event in 2017 but has since reverted to one day.
"We are at a point now where we are stagnating a bit with that one day," she told BBC Radio 5 Live's cycling podcast BeSpoke.
"There is no reason why women shouldn't have a Tour de France - I don't think it will happen in my career but hopefully in my lifetime I'll see that happen.
ASO say it is "logistically not possible" to run a 10-day race similar to the Giro Rosa, the only current women's Grand Tour event, during the Tour de France, though UCI president David Lappartient told BBC Sport he will "continue to push" the organisers for a women's equivalent.
"I'm an athlete, not a politician with a manifesto or even someone that's ever organised a bike race, but all I know is I want equality - of course it's going to be difficult but it takes people like me to push for it," added Deignan.
"This is a great event, the Tour is the biggest stage in the world and we benefit from it, but in terms of the prestige it has for riders, it's not the Giro Rosa in any shape yet."