Fabian Cancellara of Switzerland won the opening prologue of the 2007 Tour de France, posting a blistering time of 8 minutes 50.74 seconds over the 7.9km London course.
Cancellara, who will now wear the coveted race leader's yellow jersey for tomorrow's first stage from London to Canterbury, was one of the last riders to ride the course and finished on The Mall with a healthy margin of victory.
The time-trial specialist, who rides for the Danish CSC team, was about 13 seconds ahead of second-placed German Andreas Kloden while American George Hincapie finished third, a further 10 seconds back.
Britain's Bradley Wiggins, who spent much of his childhood in London in Maida Vale, came fourth, just missing out on a place on the podium.
Blazing sunshine and big crowds made for a carnival atmosphere as the Tour reached London for the first time in 104 years of existence, although Wiggins and his four fellow British riders failed to provide the storybook finish.
Enrico Degano of Italy was first to depart and finish in the 7.9km prologue around central London, starting on Whitehall and passing notable landmarks like the Houses of Parliament, Buckingham Palace and the Serpentine.
William Bonnet of France then became the man to beat, but it was when David Zabriskie of the United States descended the starting ramp that the action really started to hot up.
Zabriskie, one of few riders to have worn the yellow jersey, laid down the fastest time but almost before he had time to draw breath it was obliterated by Vladimir Karpets.
The Russian is seen as a good outside bet for the Tour, having won the white jersey for best young rider back in 2004, but he was then overtaken by compatriot Vladimir Gusev.
However, just when it looked as though it could be Russia's day, Kloden produced a devastating run to post the new mark of 9mins 03.30secs.
The German, riding for the Kazakhstan Railways-backed team of Astana, obliterated the times of the Russians.
Hincapie went second while local favourite Wiggins posted a time that put him third for a while.
But 26-year-old Cancellara's time-trial exploits had made him the pre-race favourite for the prologue and he claimed victory in style, denying Wiggins a podium finish.
Instead Wiggins had to watch as Cancellara was showered by kisses on the podium as he was presented with the yellow jersey.
He will seek to defend it in tomorrow's first stage proper, a 203km ride through London and Kent to Canterbury where Isle of Man rider Mark Cavendish will look to give the home spectators a stage win.