Cycling: Ullrich keeps up pressure as final showdown looms

American chasing a fifth consecutive title will not be able to relax as he rides towards Paris with German in close pursuit

At last. In somewhat less than an hour this afternoon, the Tour de France's hardest-fought battle for supremacy since 1989, which has kept close to half of the country's population in front of their televisions for three long, blisteringly hot weeks this July, will finally be resolved.

As showdowns go, the centenary edition of the Tour could hardly be more gripping. After more than 3,000km of racing, Lance Armstrong, who has dominated the Tour mercilessly since 1999 and who currently holds the yellow leader's jersey, is still unsure if he can take it for a fifth, record-equalling, consecutive time.

Everything still hinges on today's time trial, at 49km a mere fraction of the total distance, between Pornic and Nantes. Only a top-notch performance in this afternoon's race against the clock can ensure that the maillot jaune will still be on his shoulders for Sunday's final victory ceremonies.

Seven draining stages in the Pyrenees and Alps have steadily whittled down his rivals, leaving Germany's Jan Ullrich as the only fly left in the American's ointment - but given the fact that he is 65 seconds behind Armstrong on the overall classification, it is rather a large one.

Having been victorious in the 1997 Tour, the German is talking up his chances again after six troubled years and four runner-up places in the race, saying he has never "been so hungry for victory, never so close to doing so".

All of which means that Armstrong is finding himself under pressure as never before at this point in the race. Normally cushioned by leads of more than six minutes and preparing a triumphal ride into Paris the next day, he has won the final time trial four years on the trot purely "as a means of showing who the rightful wearer of the yellow jersey is". In other words, as a means of reminding his rivals who is boss and starting the process of intimidating them for next year's event.

Yet the 31-year-old was more than relaxed after yesterday's 200km trek north from Bordeaux to Saint-Maixent-L'Ecole. "It's the most important time trial of the five Tours I've ridden," Armstrong said. "But I'm feeling calm and confident."

However, he needs no reminding that in the 47km time trial at Gaillac a week ago he finished more than a minute-and-a-half down on Ullrich - hardly the best of omens.

Neither Armstrong nor Ullrich will spare themselves. The American's maximum gearing, a 55 chain-ring, will enable him to move 10.7 metres with each complete turn of the pedals, whilst Ullrich's 56 will gain him a further 20 centimetres.

Armstrong shrugged off Ullrich's effort to snatch back time in yesterday's stage, when he outsprinted the American for second place in an intermediate sprint, pulling back two seconds. "I don't think the Tour will be won by that kind of margin," Armstrong argued.

However, his willingness to try to sprint against Ullrich would suggest this was rather more than an attempt by the German to out-psych his opponent. Neither can the American gain too much motivation from the past: while Armstrong has won six long time trials in the Tour, Ullrich already has five in his palmares. Rather the American can draw comfort from the fact that his race condition has steadily improved in the last week.

Armstrong's victory on Monday at the Pyrenean climb of Luz Ardiden, while not on the scale of other wins in previous years, none the less regained him 40 seconds over the German and was the first positive sign that he really was in control of events.

Britain's David Millar, while counting himself out of the battle for a time trial win, feels that Armstrong has a marginally better chance of victory. "He's a lot more confident now than he was 10 days ago, and what he did on Monday shows that the old Lance has returned," the Scot argued.

After the brief skirmish between Armstrong and Ullrich yesterday, the stage win itself was decided by another break of 16 non-challengers for the general classification, with Spaniard Pablo Lastras finally securing the day's honour in a fiercely contested four-man battle.

Having edged his bike across the line less than half a metre ahead of Frenchman Carlos Da Cruz, Lastras pointed his right arm at the sky in memory of his mother, who died four months ago. "It would have been her birthday today," Lastras explained, "and I'm sure I felt her strength in me in the final metres."

His win was emotionally charged for other reasons, too. Forced to spend a total of 308 days off the bike early in his career because of numerous major injuries, it was hardly surprising that he had dedicated his first win as a pro, in a small end-of-season event in Granada in 1997, to his surgeon.

"Thankfully those days of worrying whether I'd ever get back on a bike again are long past now," Lastras said. "And I can concentrate on taking stages in races like the Tour, which is hard and challenging enough as it is."

Given the implications of today's gruelling time trial, you would imagine that neither Armstrong nor Ullrich would disagree.