Great Britain's Lizzie Armitstead was in second place as the riders turned for home in the London 2012 Olympic Games women's road race.
Armitstead was behind only Holland's Marianne Vos as they crested the summit of Surrey's Box Hill for the second and final time.
Emma Pooley was in support of Armitstead, who attacked again with 46 of the 140-kilometre route remaining, but defending champion Nicole Cooke was struggling to hang on as the relentless pace of a frantic race continued.
Holland's Ellen van Dijk launched an attack with more than 100km of racing remaining, going ahead alone, but it was quickly thwarted.
Shelley Olds of the United States and Vos of Holland were also prominent on the climb, while the descent also provided an opportunity, with Germany's Judith Arndt making a move which was followed by Vos and Pooley.
Vos made her move and went across the summit of Box Hill for the final time with Armitstead on her wheel, but the main bunch followed the move.
Russia's Olga Zabelinskaya then forged forward alone with 45km to go.
Vos caught Zabelinskaya as a group of four formed at the front, with Armitstead and Olds also present.
Armitstead took to the front to keep the pace high in a bid to keep the quartet away for the finish.
The leading group established an advantage of more than 20 seconds, with Germany leading the pursuit from the peloton. Zabelinskaya, Vos and Armitstead went ahead as Olds fell back.