Switzerland's Fabian Cancellara took the prologue at the Tour de France on Saturday. ((Pascal Pavani/Afp/Getty Images) )

Fabian Cancellara of Switzerland won the prologue of the Tour de France on Saturday, with seven-time winner Lance Armstrong finishing an impressive fourth to start what he's calling his last ride in cycling's main event.

Cancellara, who has won four Tour prologues including last year's in Monaco, clocked 10 minutes for the individual time trial on 8.9 kilometres of rain-dampened roads in Rotterdam.

"That was a great opening for me and the team," Cancellara said, referring to his Danish squad Saxo Bank. "It's an amazing day. I'm really happy."

Germany's Tony Martin, who had led for most of the day, was second, 10 seconds back, and David Millar of Britain placed third — 20 seconds off the pace.

Armstrong trailed 22 seconds back in fourth. Perhaps most impressively, the American edged out rival Alberto Contador — the defending Tour champion and top pre-race favourite -- by five seconds.

Ryder Hesjedal of Victoria was 37th, 46 seconds off the pace, while Michael Barry of Toronto was 120th, 1:08 back. The top rider for the Canadian-owned Cervelo TestTeam was Lithuanian Ignatas Konovalovas, who was 33rd, 44 seconds behind the leader.

Riders set off one by one down the starter's ramp for the race against the clock. Contador went last — right after Cancellara and Armstrong.

They took a looping course over and back across the Meuse River that cuts through Europe's largest port town, scaling three bridges including the distinctive Erasmus suspension bridge.

Fairly persistent rain left the roads shiny-wet, and bikes sizzled and spit as they cut through the water. Large crowds braved the wet weather under colourful ponchos along the route.

Martin had come saying a prologue victory was a "big goal" — and that his strategy had been to push hard from the start if rain were going to douse the roads.

Some potential Tour title contenders were already facing disappointment: Britain's Bradley Wiggins, an Olympic gold medallist and strong time-trial rider who was fourth in last year's Tour, was 77th overall — 56 seconds behind Cancellara.

Andy Schleck, who finished second in last year's Tour — one rung above Armstrong on the podium — placed 112th, 1:09 back of his Saxo Bank teammate and race leader.

Armstrong came into the time trial predicting he wouldn't win it, saying that he's "lost it" in the discipline -- one that he had dominated in his record run of Tour titles from 1999 to 2005.

But in his strong performance on Saturday, Armstrong actually appeared to slow down at one point to take a tight turn gingerly — a sign that above all he wanted to avoid a crash that could damage or derail his hopes for an eighth Tour victory.

"I've got to say I'm happy: Happy with the result, happy with the feelings, which is maybe more important than the result," he said,

"Everything from the start of the day through to the warmup just felt solid."

While he was warming up on a stationary bike, Armstrong received a kiss from his pregnant girlfriend, Anna Hansen, who was outside the RadioShack team bus with his children.

"If you would have told me this morning: 'Hey, sign up for fifth and put time on your rivals,' I would have signed with both hands," Armstrong said.

The only other time trial this year is a 52-kilometre jaunt across southwestern France in Stage 19 — on the eve of the finish on the Champs-Elysees in Paris.

But the layout also features a total of 23 mountain passes in the Alps and Pyrenees, which could play into the hands of Contador, who is considered the best climber.

Cancellara will don the race leader's yellow jersey for Sunday's 223.5-kilometre first stage across wind-swept lowlands from Rotterdam to Brussels.

The victory was another vindication for Cancellara, who has been at the centre of speculation that he benefited from a small motor hidden in his bike frame during the Paris-Roubaix race he won this year.

Cancellara has called the claims ridiculous, and they have not been proven true.

Video detailing the speculation has been a viral hit on the Internet, and partly to dampen the speculation, the International Cycling Union is scanning competitors' bikes at this Tour to check for hidden motors.

"After they checked my bike, I said, 'You should also check the motor: Me!"' Cancellara quipped.

The Swiss rider also bared a superstitious side: He says he's going to ride the whole Tour wearing his bib, No. 13, upside down — because he thinks the number otherwise might bring bad luck.

The doping spectre that has so throttled cycling's image returned. Before the start, Cervelo TestTeam said rider Xavier Florencio was suspended from competing for using a substance that contained the banned stimulant Ephedrine — fearing it could lead to a positive doping test.

The squad, led by 2008 Tour winner Carlos Sastre of Spain, was thus reduced to eight riders. The other 21 teams racing have nine.

Armstrong too faced a revival of doping suspicion that has dogged him for years.

Before the stage, Armstrong rejected as "baseless and already-discredited" claims by his disgraced former teammate, Floyd Landis, that the seven-time champion was involved in doping when they rode together. Landis' allegations, which followed similar comments he went public with in May, were published on Saturday in the Wall Street Journal.

"Landis' credibility is like a carton of sour milk: once you take the first sip, you don't have to drink the rest to know it has all gone bad," Armstrong responded in a statement.

The three-week race ends on July 25 in Paris.