The 29-year-old rider from Melbourne moved in the last climb, five kilometres from the line, with titleholder Pierrick Fedrigo of France, Germany's Paul Martens, Irish champion Daniel Martin and Frenchman Anthony Roux.

Gerrans, winner of a Giro d'Italia stage this year and a Tour de France stage last year, was by far the fastest sprinter of the five and he easily overpowered them to become the first Australian to win the Brittany race.

"I had planned to attack shortly before the top of the climb but I found myself with Fedrigo and Paul and we worked pretty well together. In the end, the fastest man won," Gerrans told reporters.

Gerrans, who started cycling to recover from a motorcycle accident at the age of 17, completed a fine double for his Cervelo team.

Britain's Emma Pooley, the Olympic silver medallist who also rides for Cervelo, won the women's event on Saturday.

Fedrigo, who beat Italy's Alessandro Ballan a year ago, had to be content with runner-up spot this time but the Frenchman, winner of a Tour stage in July, was not too disappointed.

"Ballan was second last year and he became world champion a month later. I must keep it in mind," he said.

Martens was third, ahead of Martin and Roux, with the main bunch on their heels.

One of the few ProTour races held on a circuit with 12 laps, Plouay is often seen as a good indication for the world championships, held under the same format.