Emma Pooley sprang a surprise on Nicole Cooke to prevent the latter taking a 10th consecutive national road race title in Pendle, Lancashire.
Pooley, 27, with Cervelo team-mates Lizzie Armitstead and Sharon Laws in support, pulled away towards the end of the final lap to complete her victory, with Armitstead second and Cooke third.
The women's race had earlier been halted when a pile-up shortly after the start of the event saw a number of riders injured.
The distance of the restarted race was halved from eight laps to four.
Cooke had won the previous nine national titles, and 10 of the last 11.
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