Dutch rider Marriane Vos, a former world champion, had led Britain's Lizzie Deignan by nine seconds after her stage two victory on Tuesday [until a crash today].
The peloton crash also saw the former world champion's CCC-Liv team-mates Jeanne Korevaar and Valerie Demey unable to continue as the 145.1km stage was neutralised for about 25 minutes on its way from Henley-on-Thames and finishing at Blenheim Palace.
Ten riders were taken to hospital with "minor to moderate injuries", race organisers said.