This runner finished last, but her perseverance won a nation

Runner number 401 was exhausted and suffering from low blood pressure. She also finished last in the 5,000 meters by a large margin and struggled alone, through a raucous rain shower, across the track of an almost empty stadium.

Bou Samnang, 20, finished the race anyway.

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

“I knew I wasn’t going to win, but I told myself not to stop,” 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 obligated to finish as she was representing her country.

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

A few weeks earlier, Mrs. Bou Samnang suffered a particularly severe bout of low blood pressure, a result of her chronic anemia, while she was training in the southwestern Chinese city of Kunming. A doctor told her to stop running for a while, and her coach, Kieng Samorn, insisted otherwise.

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

But Ms. Bou Samnang said she was eager to compete in the Southeast Asian Games, her first international competition, and that her coach was not standing in her way.

In the Women’s 5,000 meters final, held in a lightly attended 60,000-seat stadium, Ms. 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 just that won several gold medals at previous Southeast Asian Games.

After the starting gun sounded and the runners fell into formation, Mrs. Build Samnang into a position at the rear of the pack. In about a minute, she had fallen so far behind that she was out of much of the television coverage.

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

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

Her performance was reminiscent of other runners who persevered, including a few famously winning track events after a fall. One of them is Sifan Hassan from the Netherlands, who did this two years ago in the 1,500 meters during the Olympic Games in Tokyo.

Runners usually don’t get much credit when they lose by a wide margin. An exception is in long-distance events, where it is customary to celebrate the last finisher, said Steve Brammar, the secretary general of the Trail Runners Association of Hong Kong. A ultramarathon trail race that he directs there serves just that purpose an “Ultimate Finisher” trophy.

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

After finishing last in the 5,000 meters this month, Mrs. Bou Samnang that she could run the 1,500 meters 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 Bonus of $10,000 of Prime Minister Hun Sen and his wife, equivalent to several years of the average income of a Cambodian.

Mrs. Bou Samnang, whose father passed away in 2018, is the third of four children. She said she would use the bonus to study law at a Cambodian university, and that she intended to stay competitive.

Her mother, Mai Met, said she cried when she heard her daughter had finished last in the 5,000 metres. But that grief was tempered by the outpouring of public support that came later.

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

Her determined finish exemplified a “sports ideal,” 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 remarkable in part because Cambodian athletes generally do better in martial arts than in regional competitions.

But the example she 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 from,” he said. “When you take it in this vein, it’s something inspiring.”