Saturday's crucial penultimate stage of the centenary Tour de France should decide whether Lance Armstrong or Jan Ullrich is celebrating in Paris.
The German trails the four-time winner and reigning champion by one minute five seconds going into the 49km time trial from Pornic to Nantes.
The success - or failure - of Ullrich, the 1997 Tour champion, to make inroads into Armstrong's lead will be the decisive moment of this year's event.
The American has the clear advantage, but Ullrich will take heart from his devastating display in the first individual time trial on the Tour's 12th stage.
Then he beat Armstrong by 96 seconds and the German would be ecstatic if he were able to repeat that remarkable display.
But Armstrong ended that stage suffering from dehydration - a mistake he is unlikely to repeat.
The American has also found the form in the Pyrenees which was lacking in the Alps and he was in bullish mood ahead of Saturday's gripping stage.
"I'm relaxed. I remain confident because I've raced very
well in the last time trial over the last four years," he said.
Ullrich will take heart, however, after snipping a further two seconds off the American's lead during Friday's 18th stage.
Ullrich will hope to repeat his last time trial display
The two seconds themselves may not prove vital, but could give the German a psychological boost ahead of Saturday.
The peloton will race in reverse order for the time trial with Ullrich second last to start and Armstrong the last.
Throughout Armstrong will be informed by his team chiefs in the car that will shadow him as to whether he is losing ground on his rival as he passes the intermediate checkpoints.
Whoever takes the lead into Sunday's final stage will be a near-certainty to keep hold of it until the final ride down the Champs-Elysees in Paris.
But if it comes down to a matter of seconds, doubts are sure to creep in to both riders, increasing the possibility of errors, or even a crash.
The last time the race was this close was in 1989 when Greg LeMond overturned a small deficit at the start
of the final day to beat France's Laurent Fignon by eight seconds.
This race may not be as close, but the 100th Tour de France is certainly providing a finale to remember.