Fabian Cancellara won the Tour de France prologue in Leige, Belgium, on Saturday.
The Swiss rider fractured his collarbone in the Tour of Flanders in April.
Cancellara, 31, beat Bradley Wiggins of Britain by seven seconds.
French time-trial champion Sylvain Chavanel was third in the 6.4km time trial. Defending Tour champion Cadel Evans of Australia finished 13th.
The first stage of the race is on Sunday, 198km to Seraing. The Tour de France takes in three countries and ends on 22 July in Paris. It covers 3497km.
This year's event is the 99th running of the race. It was first staged in 1903.