Briton Lizzie Armitstead won gold in the women's road race at the Road Cycling World Championships in Richmond, Virginia.
The 26-year-old won the 130km race by a wheel from Netherlands' Anna van der Breggen, with Megan Guarnier of the United States in third.
Olympic silver medallist Armitstead said: "It's a dream come true."
The Leeds rider won silver in last Sunday's women's time trial with her Netherlands-based Boels-Dolmans team.
British Cycling president Bob Howden said: "This is a landmark moment. Lizzie represents the best of our great sport and deserves all of the praise coming her way."
Armitstead said she would "empty the tank" in the road race as she attempted to make up for the disappointment of finishing seventh last year.
But she was unable to rely on team support in the gruelling closing stages as Lucy Garner, Hayley Simmonds, Alice Barnes, Molly Weaver and Jessie Walker struggled to stay with her.
Armitstead appeared to have lost any chance of victory when she missed a breakaway of nine riders who opened up a minute's lead on the peloton with less than 10km remaining.
But the steep climbs and cobbles in the final lap took their toll on the leaders and they were swallowed up by the chasing pack.
Armitstead made her initial burst for the line with 900m to go but she could not get away. Van der Breggen then led out the final sprint but Armitstead had enough left in her legs to snatch victory.
"I just can't be believe it," said Armitstead, who last month won the UCI World Cup series for a second successive year.
"I took the decision to lead it on and then waited for the rush to come, but it never came. It will be fantastic to wear the rainbow jersey for the next year."
Armitstead becomes only the fourth British woman to win the title, following Beryl Burton, Mandy Jones and Nicole Cooke.