During his seven-year Tour reign, Lance Armstrong said that the yellow jersey wearer needed to definitively prove that he is the strongest rider in the race.
To accomplish that feat, the race leader needed to show his cards and win the final time trial. No other way proved more surely that the race winner deserved his victory.
Armstrong won the final time trial six out of seven times that he won the Tour. The only time he did not win it was in 2003, which many consider his relatively weakest performance when he barely beat rival Jan Ullrich by one minute in the end.
Race leader Alberto Contador (Astana), the national time-trial of Spain, has looked nearly unassailable in yellow thus far. After yesterday's pivotal stage into Le Grand Bournand, his closest rival, Andy Schleck (Saxobank) was already 2:26 behind. It was fairly safe to say that Contador's yellow jersey would not be challenged provided he didn't crash during the race.
Behind him, though, the race was very heated. Andy and Frank Schleck, occupying second and third overall after their escapades yesterday, are notoriously bad time-trialists compared to their rivals behind on the overall classification.
Lance Armstrong, Andreas Kloden (Astana), and Bradley Wiggins (Garmin) are all accomplished against the clock and were looking to knock at least one of the Schlecks off the podium.
Frank looked very vulnerable in third, holding barely 30 seconds over Armstrong. Andy, with a further minute's advantage over Frank, was the safer bet of the two for retaining a podium position.
Riders started in reverse order of the general classification, with the last-placed rider starting first, and the first placed rider, Contador, starting last on his ride with destiny.
As many expected, Olympic time trial champion Fabian Cancellara (Saxobank) set the fastest time of the day up to that point. He rode the course fairly early, as he was nearly two hours behind in the GC.
Cancellara's time looked very tough to beat. Holding a time of 48:33 around the 40-kilometer course, the Swiss rider averaged an impressive 49.5 kph around the rolling course with a 5-kilometer-long climb in the middle.
Later on, the big guns came out to play. Many eyes were on Olympic pursuit champion Wiggins as a likely candidate to move back up onto the podium and possibly win the stage.
Armstrong left after Wiggins to many cheers and plenty of video coverage. Riding yet another custom-painted Trek bicycle, he blasted out of the start house and looked like the Armstrong who won the many Tours.
Frank and Andy Schleck then left the start house, their mission to limit their losses on the chasers, and finally yellow jersey Contador set out on the road to distance his rivals even more.
As riders passed intermediate checkpoints, the race for the stage win and overall classification started to take shape. Wiggins blasted around the first checkpoint with the fastest time, setting the foundation for a stage win. Armstrong was not far behind.
Frank Schleck, not surprisingly, set only a mediocre time and had already lost his third place overall position. Andy, though, came into the checkpoint only around 10 seconds off of Armstrong. Clearly the younger Schleck was having a good ride on today's crucial stage.
However, no one could touch the time of Contador. Not content to just limit time losses, Contador set the fastest time at the first time check, nearly 20 seconds ahead of Cancellara's and many more ahead of his direct rivals.
As the riders progessed, Frank Schleck put in his expected ride and rode off the podium. Armstrong set very good times as Wiggins started to fade, and his stage win hopes looked threatened. Andy Schleck was still holding his own, only 15 seconds behind Armstrong.
When the finish finally arrived, Wiggins faded dramatically to come in 40 seconds behind Cancellara. Armstrong came in at 50 minutes flat, 1:27 behind Cancellara. His teammate Andreas Kloden came in ahead of him, but still 50 seconds behind Cancellara.
Andy Schleck put in an impressive ride for his skinny build and finished only 15 seconds behind Armstrong to more than preserve his second place overall.
The podium was starting to shape up. Armstrong moved up into third place, Wiggins into fourth, only 11 seconds behind Armstrong in the overall. To make things even more interesting, Kloden was in fourth only a further two seconds off Wiggins. The competition for the final podium spot might be the most fierce going into Paris.
Behind all these riders, though, no one could touch the yellow jersey. The lightly built 62-kilogram Spaniard, not typically suited to a power course like this, set all intermediate checkpoints on fire. Blazing into the finish, he barely managed to break the very long-standing time of Cancellara by two seconds.
Contador proved to all that he is the strongest rider in the race, just like his now-teammate Armstrong proved many times in the past.
Cancellara, who held the fastest time all day, was finally relegated to second place. Mikhael Ignatev (Katusha) put in a very strong ride to finish third on the day.
Once again, the overall classification shakes up greatly for the second day in a row. Contador firmly pounded rivals into submission. He finished over 40 seconds ahead of nearest GC rival Wiggins.
Contador assumes a commanding lead of 4:11 over Andy Schleck, 5:25 over Armstrong, 5:36 over Wiggins, and 5:38 over Kloden.
Tomorrow's Stage 19 will offer considerably less excitement than today's time trial, but it will serve as an active rest for the overall riders as they prepare for Saturday's leg-busting stage up to the top of the infamous Mont Ventoux.
As in many year's past, even the sprinters' teams may not be willing to give chase, allowing a breakaway to succeed as it has so many days so far this Tour.