BARCELONA, Spain - A split second off the lead with the mighty Pyrenees looming, Lance Armstrong now gets to see what his rivals can throw at him.
After mostly flat, wind-swept stages along the Mediterranean rim this week, the Tour de France enters mountainous terrain that has long belonged to climbers.
Armstrong remained just a fraction behind overall leader Fabian Cancellara of Switzerland on Thursday after a treacherous, rain-soaked ride filled with crashes. Thor Hushovd of Norway led a mass sprint finish to capture the 113-mile sixth stage from Gerona to Barcelona.
The field faces a 139-mile haul from Barcelona to Andorra today with a grueling uphill finish - the first and hardest of three days in the Pyrenees.
"Tomorrow is an important day," Armstrong said. "I don't know if it's the most important day, but it's definitely a big appointment on this Tour."
The seven-time champion said he was happy to emerge unscathed from Thursday's "nervous" ride. Two spills marred the last six miles - one involving Yukiya Arashiro of Japan, another involving former world champion Tom Boonen of Belgium, one of Hushovd's sprinting rivals.
Cancellara, a time trial specialist, acknowledges he's not the best climber and his six-day run in the front may soon end.
"What do I have to do tomorrow? It's a good question," he said. "It's been a beautiful week to be in this yellow jersey. ... I'm going to try to defend it but I don't know how well I can do."