Tour leader David Zabriskie found the road ahead a lonely one after he took a spill in the closing moments of Stage 4 Tuesday. AP
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Tour leader Dave Zabriskie lost the yellow jersey two ways in Tuesday's fourth stage: gradually, then suddenly. While his CSC team posted the fastest time checks throughout the team time trial -- a tailwind-assisted, 67.5-kilometer dash along the Loire River, from Tours to Blois -- the Danish squad was uneasy.

That's because Lance Armstrong and his Discovery Channel team kept nibbling away at their lead. The last team to leave the starting line in Tours, CSC was 15 seconds ahead of Armstrong & Co. at the first time check (25 km). By the second check (45.8 km), that lead had been whittled to six seconds. At the final time check, six kilometers from the finish, CSC was just two seconds up. And then they were down.

So was Zabriskie, who caromed off a barrier on the main drag into Blois, pin-wheeling along the pavement at 30 mph, his clothing and epidermis peeling off on President Wilson Avenue while his teammates swerved to miss him. I still can't tell whether Zabriskie's front wheel touched the rear wheel of the rider ahead of him, or if a gendarme got in his way. (As Zabriskie falls hard onto his left side on the Outdoor Life Network replay, you see a French cop hucking himself up over the barrier, the way an NHL line judge hoists himself up on the dasher to get out of the way of the play.)

However it happened, Zabriskie's brief spell in yellow came to a shockingly abrupt end. Mindful of the need to preserve the standing of Ivan Basso, their real team leader, CSC's upright riders soldiered on, leaving Zabriskie to pick himself up, mount a replacement bike and wobble to the finish, solo, bloodied and missing much of the left side of his racing shorts. Also frayed was the yellow jersey he'd worn since winning the opening time trial, and would soon give up. Proclaimed Outdoor Life Network's Phil Liggett, "And the maillot jaune is sullied."

But not for long, as moments later, Armstrong slipped into a fresh, untattered yellow jersey. Zabriskie's tumble cost his team at least a few ticks of the clock, and that was enough for Discovery to carry the day. CSC lost the stage by 1.79 seconds, giving Discovery its third straight victory in this riveting discipline -- is it not stunning, the sight of nine streamlined riders sustaining speeds close to 40 mph? -- and nudging Armstrong into the top spot in the general classification.

Martin Dugard, who is filing daily dispatches for Competitor.com, told me over the phone that while Armstrong was expansive and ebullient after the stage, the post-stage CSC press conference was funereal. That's not surprising: Team director Bjarne Riis had put heavy emphasis on today's stage in the squad's preparation. He even left Jakob Piil -- a proven flatland rider who exudes power and ultra aggressiveness -- off the squad in favor of Luke Roberts, a young Aussie whom, it was thought, would be of more assistance to CSC in the team time trial.