Jessie Diggins wins silver for the U.S., her third Olympic medal.

Less than two weeks ago, Jessie Diggins won a bronze medal in the women’s sprint, the first individual Olympic medal won by an American woman in cross-country skiing.

On Sunday, Diggins, the biggest cross-country star from the United States, further proved her dominance by winning silver in the women’s 30-kilometer freestyle, a marathon race that is a world away from the sprint.

She finished the race in 1 hour 26 minutes 37 seconds, behind only Therese Johaug of Norway (1:24:54). Kerttu Niskanen of Finland was third.

Rosie Brennan of the United States finished sixth.

The event was Diggins’s sixth race at these Winter Games, a relentless schedule with a grueling endurance event as the cherry on top. Conditions added to the grit: The race’s start was moved ahead by three hours to avoid high winds.

But grueling is Diggins’s specialty. Last year, she won the Tour de Ski, an eight-stage race held over 10 days. She was the first American to win the tour, the marquee event of the World Cup cross-country ski circuit.

Diggins said later that the Tour de Ski was “almost comical, how brutally hard it is.” But she strives toward a “pain cave,” she has said, because “fast is fun.”

When Diggins finished Sunday’s race, she collapsed on the snow, disbelief painted across her face. She was helped away from the finish area by her teammates.

Afterward, Diggins said in a television interview that she had food poisoning 30 hours before the race, “which is why I thought I was going to die at the finish line.”

“My legs were cramping the whole last 17K,” Diggins said. “I don’t know how I made it to the finish.”

As the de facto leader of the U.S. team, Diggins continues to show other American cross-country skiers that they can compete with the Scandinavians who have long dominated the sport.

Sunday’s race was no different. She was in second place for the majority of the race, skiing mostly alone between the Norwegian leader and the rest of the field. She became the first non-European skier to win an Olympic medal in the event.

The event was raced in the freestyle method, Diggins’s specialty, which resembles the angled movements of roller skating. At the 2018 Olympics, the 30K was raced in the classical style, in which the athletes keep their skis parallel, often in manicured paths. Diggins finished seventh that day.

Diggins now has a silver and bronze to add to her gold medal, won in 2018 in the women’s team sprint with Kikkan Randall. Over nearly 100 years, the United States had won only a single medal in cross country at the Olympics, in 1976. Now Diggins has won three in four years.