"Awesome," Armstrong mumbled through her tears as she wrapped her arms around husband Joe Savola at the finish line. "It's so awesome."
Christine Thorburn was fifth in the race for the US team, missing a medal by about three seconds in her Olympic farewell.
Switzerland's Karin Thurig was third, about a minute off Armstrong's time. French legend Jeannie Longo-Ciprelli - 49 years old, in her seventh Olympics - was fourth, just ahead of Thorburn, whose in-helmet radio conked out during the race and left her unable to know split times.
Nonetheless, Thorburn was thrilled for Armstrong.
"She's been preparing impeccably for the last four years, frankly," Thorburn said. "She was totally ready and totally deserving."
It completes a stirring cycle for Armstrong, who turned to cycling only after arthritis in her hips forced her to abandon a career as a professional triathlete. She made the 2004 Olympic team, but was left off the two-woman roster for the time trial in Athens, a decision that pained her deeply.
In the end, it worked out perfectly.
"The moment that I had today, it's one of those dreams you have as a child in America," Armstrong said.
And now, maybe she'll stop being asked if she's related to that other Armstrong, the one named Lance who has seven Tour de France championships on his résumé. (She's not.) She one-upped Lance yesterday - his best Olympic finish was a bronze.
The seeds for this Beijing triumph were planted halfway around the world, in her hometown of Boise.
Using GPS equipment and Google maps, Armstrong somehow figured out there was a course on nearby Idaho roads that almost perfectly matched the climbs and descents of the terrain in Beijing. So for six weeks before heading to China, she trained over and over on that stretch of road, hoping for a little hometown advantage in Beijing.
"Man, it's indescribable," US coach Jim Miller said. "We had splits we wanted to hit from the get-go and she was on top of every one. . . . There wasn't a stone we left unturned and she got the reward."
