He then stole all the headlines with an endearingly frank plea for all the teams in the peloton to abandon what he referred to as the "old school way" of doing things. Which, in cycling, means doping. Gerdemann's own team, T-Mobile, has a strict internal anti-doping testing programme, and the young German used the victory stage to issue a call for others to follow suit.

"The sport gave us this past, but I don't just want to say that T-Mobile is doing something to take cycling a better way," said Gerdemann. "We have a clean way as a team, but we all have to do it, all the teams. We are not at the finish line, but I believe that many teams are changing. The old school way is not the way any more."

With the jagged profile of the Alps dominating the skyline, yesterday's seventh stage saw the first proper skirmishes of this year's Tour, but it wasn't quite tough enough to provide the "sort out", so often supplied by this terrain. As the riders tackled the lower slopes of the day's biggest climb, the Col de la Columbiere, there was even the faintly surreal sight of David Millar at the front of the dwindling peloton.

The tall Scot looked to be climbing comfortably, encouraging speculation that he might be in yellow for today's far tougher stage to the ski resort of Tignes.

The speculation was based on Millar's overall position in the morning - fourth - and the fact that two of those above him, the yellow jersey Fabian Cancellara and Filipo Pozzato, had been dropped. Only Andreas Kloden seemed to stand in the way, and the German has been racing since Thursday with a hairline fracture of the coccyx.

But hopes of a British yellow jersey, at the end of a notable week for British cycling, were extinguished as the slope steepened. Millar was in a small group that dropped out the back of the 40-strong lead group, as, up ahead, Gerdemann was making the move that would settle the destination of the leader's yellow jersey.

Thousands lined the narrow mountain road - many waving the Tricolore - leaving a thin corridor for the riders to race through, and through those crowds Gerdemann, who was in the day's early 15-man break, emerged at the head of the race with one other rider, Dimitri Fofonov. With 20km to the finish - still around 10km from the summit - Gerdemann launched a ferocious attack, to which Fofonov couldn't respond.

The German crossed the summit alone, and then executed the most hair-raising - or just plain crazy - of descents into the small town of Le Grand-Bornand. At points he perched on the top tube of his frame, making himself extremely small - and shaped like a bullet - as well as very unstable. But he survived into the town and enjoyed the victory, before being presented with two jerseys: yellow for overall winner, white for best young rider.

The origins of Gerdemann's "difficult" reputation are hard to trace, though some say that it began at his previous team, CSC, apparently forged on one of the Danish team's notoriously tough team-building camps.

Difficult or not, he is highly intelligent and articulate and spoke eloquently, in perfect English, about his win, and about cycling's image problem. He revealed yesterday that he has already been subject to two blood volume tests - conducted by T-Mobile - in the opening week of this Tour. "Cycling has big problems, for sure, and it is really, really hard for young riders to accept all the responsibility for that," said Gerdemann. "But I want to say thanks to the supporters - especially in London last weekend and today. It was unbelievable. I say thanks to them for their belief and their support."

With his comments, Gerdemann struck the perfect note. The opening week to the 2007 Tour has been mercifully free of scandal, if not incident. Mostly these have affected the Astana squad, which started as the most formidable on paper, but which has been decimated in the opening week. Or, more specifically, on Thursday's stage from Chablis to Autun.

It should have been fairly routine, but first Kloden, third overall last year, was dumped into a ditch; and no sooner had Kloden returned to the peloton than Alexandre Vinokourov, the favourite, suffered an horrific crash, which left him with deep wounds to his knees, right hip and elbow. He started on Friday bandaged up and held together with 37 stitches.

Yesterday was the bigger test, and he came through unscathed - or as unscathed as someone so heavily bandaged can look.

Otherwise the Tour began positively and built up considerable momentum over two spectacularly successful days in the south of England. After the London start, Sunday's stage was witnessed by huge crowds - the fairly meaningless "estimates" ranged from 1.5 to three million - and they were treated to a long break by Millar, who vied with Bradley Wiggins for the title of most popular rider en route.

The five-strong British contingent - there is also Mark Cavendish, Charly Wegelius and the youngest rider in the race, 21-year old Geraint Thomas - admitted when the race returned to France that their continental colleagues had been stunned by the reception in the UK.

Millar, who is penning a richly entertaining daily blog, wrote afterwards that his break had "started off as an adventure to give the British public something to cheer about, and something to remember" - recalling that in 1994, when the Tour last visited the UK, he had been roadside and inspired by an aggressive display by Chris Boardman. "There were moments when it was so thick with people, when I was out on my own, that I actually got goosebumps," wrote Millar of his great escape. He has promised more - and that one of them will nab him a stage.