Nicole Cooke's fifth place at the Nürnberg meeting in Germany was enough to secure the World Cup series.
The 20-year-old Wick cyclist becomes the youngest ever winner of the Cup and the first Briton to achieve the honour.
The race was won by Cooke's teammate Diana Ziliute, but she finished ahead of closest rivals Judith Arndt, Sara Carrigan and Mirjam Melchers, and none of those can now catch the Welsh rider in the overall standings.
Ziliute beat Regina Schleicher (German National Team) and Arenda Grimberg (Farm Frites-Hartol) in a bunch sprint at the end of the 117km race.
"It was a funny feeling crossing the line because I already knew I was going to win the World Cup series," Cooke told her official website.
"Crossing the line last week in Plouay was more emotional because that's where I really won it.
"Obviously I'm really happy to have clinched it today but I'm more delighted that Diana was able to win the sprint.
"I could probably have finished better than fifth but didn't want to take away Diana's chances.
"My team have been fantastic, now I can concentrate on the World Championship in Canada in October.
"I'll ride the Rotterdam Tour staring tomorrow and we'll see how it goes in the final race next weekend."
1 Diana Ziliute (Ltu) Acca Due O Pasta Zara Lorena Camicie 2.53.49 (40.39 km/h)
2 Regina Schleicher (Ger) German National Team
3 Arenda Grimberg (Ned) Farm Frites-Hartol Cycling Team
4 Anita Valen (Nor) Bik-Powerplate
5 Nicole Cooke (GBr) Ausra Gruodis-Safi
6 Mirjam Melchers (Ned) Farm Frites-Hartol Cycling Team
7 Rochelle Gilmore (Aus) Ausra Gruodis-Safi
8 Petra Rossner (Ger) Equipe Nürnberger Versicherung
9 Rachel Heal (GBr) British National Team
10 Tanja Hennes (Ger) Team Next 125
World Cup standings after round 8
1 Nicole Cooke (GBr) Ausra Gruodis-Safi 309
2 Mirjam Melchers (Ned) Farm Frites-Hartol 183
3 Regina Schleicher (Ger) 181
4 Sara Carrigan (Aus) Powerplate Bik 173
5 Judith Arndt (Ger) Nurnberger 157
6 Anita Valen (Nor) Powerplate Bik 127