Runner number 401 was dead tired and suffering from low blood pressure. She was also last by a wide margin in the 5,000 meters, trudging alone, through torrential rain, around the track in an almost empty stadium.

Bou Samnang, 20, completed the race anyway.

Her rain-soaked performance at the Southeast Asian Games – this year’s edition was hosted this month by her native Cambodia – would have been a footnote in a tournament unknown to most sports fans outside the region. But when video of it circulated widely on social media, she became an unlikely national celebrity.

“I knew I wasn’t going to win, but I told myself I wasn’t going to quit,” she said in an interview.

As she struggled on, it helped that a small group of supporters applauded furiously, she added, and that she felt a duty to finish because she was representing her country.

Bou Samnang, who graduated from high school last year, did not expect to attract international attention when she arrived on May 8 for the 5,000-meter final in Phnom Penh, the capital and her hometown. She was grateful just to compete.

A few weeks earlier, Bou Samnang had suffered a particularly bad bout of low blood pressure, 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 coach, Kieng Samorn, didn’t insist otherwise.

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

But Bou Samnang said she was eager to run in Southeast Asia, her first international competition, and that her coach was not standing in her way.

In it 5,000 meters women’s final, held in a well-attended 60,000-seat stadium, Bou Samnang gathered at the starting line alongside some of the region’s best runners. The eventual winner, Nguyen Thi Oanh of Vietnam, is an Olympian who had won several golds at previous Southeast Asia games.

After the starting gun sounded and the runners fell into formation, Bou Samnang took a position towards the back of the pack. Within a minute or so she had ended up so far behind that she was not seen in much of the television coverage.

But she continued, even as Ms. Oanh and other runners stopped, the heavens opened and some fans lost interest.

Bou Samnang would finish in 22 minutes and 54 seconds – almost six minutes behind Vietnam’s Oanh and about 90 seconds behind compatriot Run Romdul. By then the stadium floodlights were off, the water pooled on the track and her pink shoes and red uniform were completely soaked.

Her performance was reminiscent of other runners who persevered, including a few who famously won track events after falling. One is Sifan Hassan in the Netherlands, who did it in the 1,500 meters at the Tokyo Olympics two years ago.

Runners don’t tend to win much praise if they lose by a wide margin. An exception is in long-distance events, where it is customary to celebrate the last finisher, says Steve Brammar, general secretary of the Trail Runners Association of Hong Kong. One ultramarathon trail race which he directs there has an “Ultimate Finisher” trophy for that very purpose.

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

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

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

Her mother, Mai Met, said she cried after hearing her daughter had finished last in the 5,000m. But that sadness was tempered by the public support that came later.

“I’m happy,” said Mai Met, 44, who has long supported the family by working in garment factories.

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

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

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

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