Runner number 401 was dead tired and suffered from low blood pressure. She was also last by a wide margin in the 5,000 meters and lumbered alone, through a screaming storm, around the track of a nearly empty stadium.

Bou Samnang, 20, finished the race anyway.

His performance in the rain at the Southeast Asian Games (this year’s edition was hosted this month by his home country of Cambodia) would have been a footnote in a tournament that is unknown to most Asian fans. sport outside the region. But when the video circulated widely on social media, she became an unlikely national celebrity.

“I knew that I would not win, but I told myself that I should not stop,” he said in an interview.

As he trudged along, it helped that a small group of supporters were applauding furiously, he added, and that he felt a duty to finish because he represented his country.

Ms. Bou Samnang, who graduated from high school last year, did not expect to attract international attention when she arrived for the 5000m final in Phnom Penh, the capital and her hometown, on May 8. She was grateful to be competing.

A few weeks earlier, Ms. Bou Samnang had suffered a particularly severe episode of low blood pressure, as a result of her chronic anemia, while training in the southwestern Chinese city of Kunming. A doctor told her to stop running for a while and her trainer, Kieng Samorn, did not insist otherwise.

“He has a health problem,” Kieng Samorn said. “We can’t force her.”

But Ms. Bou Samnang said she was looking forward to participating in the Southeast Asian Games, her first international competition, and her coach did not stand in her way.

In it Women’s 5,000 meter final, held in a low-attendance 60,000-seat stadium, Ms. Bou Samnang met at the start line alongside some of the best runners in the region. The eventual winner, Nguyen Thi Oanh of Vietnam, is an Olympian who had won several golds in previous Southeast Asian Games.

After the starting gun sounded and the riders formed up, Ms. Bou Samnang moved to the back of the pack. In about a minute, she had fallen so far behind that she was not visible on much of the television coverage.

But she kept going, even when Ms. Oanh and other runners finished, the heavens opened up and some fans lost interest.

Ms Bou Samnang would finish in 22 minutes 54 seconds, almost six minutes behind Vietnam’s Ms Oanh and some 90 seconds behind her compatriot Run Romdul. By then, the stadium lights were off, water was pooling on the track, and her pink shoes and her red uniform were soaked through.

His performance reminded other runners who persevered, including some who won track events after falling. One is Sifan Hassan from the Netherlands, who did it in the 1,500m event at the Tokyo Olympics two years ago.

Running backs don’t usually earn much praise if they lose by a wide margin. An exception is long-distance events, where it’s common to celebrate the last runner, said Steve Brammar, secretary general of the Hong Kong Trail Runners Association. A ultramarathon race that he runs there has an “Ultimate Finisher” trophy just for that purpose.

Ms. Bou Samnang’s “perseverance was inspiring and really seems to have warmed hearts and captured imaginations,” Mr. Brammar said in an email.

After finishing last in the 5,000-meter race this month, Ms. Bou Samnang’s health prevented her from running the 1,500-meter race as planned, her coach said. But after a video of her determined performance circulated online, she received public praise of the King of Cambodia and a $10,000 bonus of Prime Minister Hun Sen and his wife, equivalent to several years of income for an average Cambodian.

Ms. Bou Samnang, whose father died in 2018, is the third of four children. She said that she would use the bonus to study law at a Cambodian university and that she planned to continue competing.

Her mother, Mai Met, said she cried when she found out her daughter had finished last in the 5,000-meter race. But that sadness was mitigated by the outpouring of public support that followed.

“I am delighted,” said Ms. Mai Met, 44, who has long supported the family by working in garment factories.

His determined finish illustrated an “ideal of sport,” said Edgar K. Tham, a sports psychologist in Singapore who works with athletes in Southeast Asia.

He said the attention Ms. Bou Samnang has received is notable in part because Cambodian athletes tend to do better in combat sports than in regional competitions.

But the example he set, he added, will resonate far beyond Southeast Asia.

“That’s what life is all about: moving forward and using failures as lessons to bounce back,” he said. “If you take it in this spirit, it’s kind of inspiring.”