Peres Jepchirchir of Kenya broke away late in the race to sprint to the gold medal in the women’s marathon.

Jepchirchir was among a large pack of runners that held together on Saturday morning until the late going. She went on to defeat another Kenya runner, Brigid Kosgei, the world-record holder, who earned the silver medal, and Molly Seidel of the United States, who claimed the bronze.

Jepchirchir won in 2 hours 27 minutes 20 seconds. She was 16 seconds ahead of Kosgei and 26 seconds ahead of Seidel.

Officials moved the race in 2019 to Sapporo, 500 miles north of Tokyo, in a futile attempt to escape the sapping heat and humidity that have smothered the Summer Games.

Seidel, running only her third marathon, won a surprise bronze in 2:27:36. She became the third American woman to win a medal in the Olympic marathon since Joan Benoit Samuelson won the inaugural race at the 1984 Los Angeles Games and Deena Kastor took bronze at the 2004 Athens Games.

Hours before the start, the marathon was moved up an hour to 6 a.m. to slightly moderate the effects of a record heat wave on Hokkaido, the northern Japanese island where Sapporo is located. But it was swampy at 78 degrees Fahrenheit, with 82 percent humidity. The race began with many of the runners wearing hats and sunglasses and trying to find narrow areas of shade at a cautious pace. Many of the 88 entrants, perhaps a third of them, were expected to drop out.

The winning time was the second slowest of the 10 women’s Olympic marathons, but time did not matter on Saturday. Survival mattered. Winning mattered.