Molly Seidel of Wisconsin was not supposed to make the U.S. Olympic marathon team.
The Olympic trials last year in Atlanta had been her first attempt at the 26.3-mile race.
On her third try Friday, Seidel did one better. She stuck with some of the world's best distance runners to finish third in the punishing heat and humidity in Sapporo, Japan.
Seidel joined Joan Benoit Samuelson and Deena Kastor as the only American women to reach the podium in an Olympic marathon, winning the bronze medal in a time of 2 hours, 27.46 minutes.
Seidel was 26 seconds behind winner Peres Jepchirchir of Kenya, who made a late charge to take the gold medal.
"This is the day you dream of your entire life," she said. "This is what it means to be an athlete."
Jepchirchir dropped favorite Brigid Kosgei of Kenya in the final mile to win easily. Kosgei held off Seidel by 10 seconds for the silver medal.
The winning time was well off Kosgei's world record of 2:14.05 as the runners struggled in muggy conditions. Race officials moved the start time up an hour to 6 a.m. because of the weather.
The change announced the night before threw off Seidel's pre-race planning.
"Everything getting to the start line of this race has been crazy and that was another little bit of crazy thrown in there," she said.