Laura Muir became the third British woman to win a Diamond League title thanks to her second-place finish in the 1500m in Zurich on Thursday.
The Scot, 23, was pipped on the line by American Shannon Rowbury but overtook Kenyan Olympic champion Faith Kipyegon in the overall standings.
Kipyegon could only finish seventh.
"I never expected anything like this," said Muir, who was seventh in the Olympic final in Rio. "I am the Diamond Race winner. This is big, big for me."
Muir beat her own British 1500m record by more than two seconds to win last week's Diamond League race in Paris. She also won in London.
The title earns the veterinary medicine student a prize of £30,000.
South African Olympic gold medallist Caster Semenya won the 800m to seal the overall title.
She beat Francine Niyonsaba of Burundi and Kenya's Margaret Nyairera Wambui into second and third, a repeat of the Olympic final in Rio.
Britain's Lynsey Sharp finished 11th.
Double Olympic sprint champion Elaine Thompson won the 200m race in 21.85 seconds, beating rival Dafne Schippers by 0.01 seconds, with Britain's Dina Asher-Smith finishing fourth.
Despite finishing second, Schippers won the overall Diamond League trophy.
French pole vaulter Renaud Lavillenie, who was reduced to tears on the Olympic podium in Rio last month after losing his title, was crowned Diamond League champion for the seventh season in a row.
He finished joint first with Sam Kendricks of America in Zurich, with Olympic champion Thiago Braz da Silva finishing third.
Watch highlights of the Diamond League meeting in Zurich on BBC One on Saturday 3 September at 13:10-14:15 BST.