SEOUL — South Korea's ruling party has won a historic landslide win in parliamentary elections, delivered largely by its handling of the coronavirus outbreak.

President Moon Jae-in’s Democratic Party, together with a small satellite party, won 180 seats in the 300-seat national assembly, the biggest majority any party has won since the country’s transition to democracy in 1987, results announced Thursday showed.

Turnout was 66.2 percent, the highest in a general election since 1992, as the government surmounted the logistical challenges of holding an election during a pandemic, and the electorate determined not to let the virus prevent them casting their ballots.

Many people had cast their ballots last week during two days of early voting, which helped reduce the crowds on the official election day.

Park Sang-chul, a professor of politics at Kyonggi University, said the coronavirus turned out to be a political blessing for Moon and his party.

“The sluggish economy and corruption scandals that have been bogging down the Moon government were dramatically overshadowed by its effective management of the coronavirus crisis,” he said. “The virus is a life-or-death matter.”

Moon was criticized in the early days of the outbreak for delaying a ban on travel from China and downplaying the crisis, arguing in mid-February that the coronavirus would “disappear before long,” just before cases surged. An online petition calling for his impeachment drew more than a million signatures that month.

But South Korea has since emerged as a model of how to bring the coronavirus under control, through an extensive system of testing, tracing and monitoring. Without imposing a lockdown, it has brought the number of new infections down to below 50 a day, from a peak of 909 in late February.

During the campaign, the ruling party emphasized the government’s response to the coronavirus. The opposition credited the Korea Centers for Disease Control and Prevention and health professionals on the front lines, as well as the Korean people for adhering to health guidelines.

Moon’s success, Park said, would send a message to other political leaders around the world as they struggle with the challenges posed by the coronavirus.

The way South Korea handled the logistical challenges of holding the first national elections in the midst of a coronavirus pandemic will also be closely watched.

On her second day of mandatory self-quarantine on Wednesday, Jung Min-ji was allowed out for 100 minutes to vote.

She put on a mask and walked to a polling station, the sole permitted destination. Her walk was location-tracked by a government app on her smartphone developed to monitor quarantined citizens. After regular voters had left, she entered the polling booth, cast her ballot and returned home to continue with her two-week isolation.

The government put in an immense amount of preparation to enable 44 million eligible voters to cast ballots.

An extensive package of safety measures was put in place to ensure that voters could leave their homes and join the lines at polling stations without spreading the infection.

On Wednesday, voters in masks stood at three-foot intervals to enter polling booths. Officials took their temperatures at the gate and directed anyone with a reading above 99.5 Fahrenheit (37.5 Celsius) to a separate polling area. Each voter was given a plastic glove before entering the polling booth, which was disinfected regularly.

For the more than 3,100 coronavirus patients in the country, officials in hazmat suits set up polling stations at eight main quarantine centers.

The 60,000 South Koreans under quarantine at their homes, like Jung, were given a special time slot at voting stations after polls officially closed at 6 p.m. to ensure they could cast their ballots without crossing paths with regular voters.

The pandemic has disrupted the primary season in the United States, forced local elections to be delayed in European countries and prompted Poland to plan a mail-in ballot for its upcoming presidential election.

South Korea’s election illustrates both the challenges to democracy posed by the coronavirus and how they can be overcome. The country has never delayed an election, even during the Korean War or the 2009 outbreak of H1N1 influenza.

The Seoul government has the legal authority to cite a national calamity to postpone the election, but postponing was “out of the question for South Koreans,” said Duyeon Kim, a Korea expert at the International Crisis Group.

“South Koreans have trauma from two authoritarian regimes between 1963 and 1988, so elections are particularly essential to their democracy,” Kim said, referring to periods of postwar military rule.

Jung flew home from Sydney earlier this week after her working holiday there was disrupted by the pandemic, and she made sure she got back in time for the elections. She was immediately placed in quarantine.

“Especially in these trying times, I felt the importance of my right to vote,” she said.

Moon’s approval rating stood at 55 percent this week, according to one closely watched poll, an increase of more than 10 percentage points since January.