Dutchwoman Marianne Vos put years of frustration behind her when she claimed the gold medal in the Olympic cycling road race, dashing Britain's hopes of a first home victory of the Games.

Vos, runner-up in the last five editions of the road race world championships after her 2006 win, outsprinted breakaway companion Lizzie Armitstead, who at least earned Britain their first medal of the London Olympics.

Russian Olga Zabelinskaya, also featuring in the breakaway, took third place at the end of a 140.3-km ride starting and ending on The Mall.

"I'm so glad I committed to that break," Armitstead told reporters.

"We saw the men's race. Once you've got a committed group it's hard to get them back so I went with it" - Lizzie Armitstead

"I should have just jumped her there. Marianne was the one to watch so I was following her around." 

Four riders were left to contest the three medals when Vos, Armitstead, Zabelinskaya and American Shelley Olds powered away from the main bunch after the second and last climb to Box Hill.

Italy, Sweden and Germany, looking to bring their leaders back into the picture, took turns at the front of the peloton but the leading four collaborated well to build a decent gap.

Olds's hopes, however, vanished when she suffered a puncture with 25 kilometres to go.

Vos, the 2008 points race Olympic champion on the track, timed her final effort to perfection as she surged past Zabelinskaya in the final straight with Armitstead being slightly too slow to latch on to her wheel.