But as the leaders sprinted up the Champs Elysees in Paris on Sunday, it was Armstrong's teammate Alberto Contador who took first place, reports CBS News correspondent Elizabeth Palmer.
Armstrong finished in third place, crossing the finish line more than five minutes after Contador.
The American cyclist, now 37 years old, says he's still proud of the result.
"Hey, I can't complain. For an old fart coming in here and getting on the podium with these young guys - not so bad," Armstrong said.
Over the finish line, Armstrong raised a paper cup to one of the most demanding and famous races in the world.
The course loops 2,200 miles around France - the equivalent of cycling from New York to Salt Lake City.
Riders average 25 miles an hour over the course. The race includes 64 uphill sections - the most grueling of which is 13 miles long.
Armstrong made cycling history when he won the Tour de France every year between 1999 and 2005.
This was his first Tour after a four-year break, and, says Armstrong, it was just a warm-up.
He's already setting his sights on his next win -- in 2010.