Lizzie Armitstead made it two victories from two races in 2016 by winning the Italian one-day classic Strade Bianche on Saturday.
Armitstead (Boels-Dolmans) formed part of a three-rider escape and then attacked again on the uphill finish into Siena to beat Poland's Katarzyna Niewiadoma (Rabobank-Liv) into second place by three seconds and Sweden's Emma Johansson (Wiggle-High5) into third by 13 seconds.
The race, which takes its name from the sections of gravel roads it takes place on, was the first instalment of the new women's UCI WorldTour and Armitstead consequently moves to the top of the rankings.
The 27-year-old world champion said: "We shared the work in the last 10km and I pulled away on the climb. It worked out really well."
Armitstead got her season off to a triumphant start by winning Omloop Het Nieuwsblad last weekend.
Result
1 Lizzie Armitstead (GB) Boels-Dolmans, 3:30:13
2 Katarzyna Niewiadoma (Pol) Rabobank-Liv, +3secs
3 Emma Johansson (Swe) Wiggle-High5, +13
4 Elisa Longo Borghini (Ita) Wiggle-High5, +1:04
5 Anna van der Breggen (Ned) Rabobank-Liv, +1:07