South Korea regained the Olympic women's short track 3,000m relay gold yesterday, four years after its Vancouver medal hopes were dashed by disqualification.

Shim Suk-lee passed China's Li Jianrou heading into the final turn to give the Koreans Olympic gold for the fifth time in the past six Olympics. Defending champion China was disqualified for impeding on the final lap, promoting Canada to silver and Italy to bronze.

The Korean team of Cho Ha-ri, Kim Alang, Park Seung-hi and Shim finished in 4min 9.498sec, with Canada crossing the line in 4:10.641. "I felt really good going into the last lap," Shim said. "I felt fast, and I thought I could pass Li. And it was such a thrill when I did."

South Korea and China exchanged the race lead five times in the last eight laps in a battle that was back and forth from the start. Like their opponents four years ago, the Chinese were devastated following the race.

"According to the judges, when Zhou (Yang) exchanged, she was on the track and impeded skaters behind her," said Chinese coach Li Yan.

"But according to what I saw, there were two to three meters between her and the Korean skater, and a skater is allowed to go on to the track when they exchange. But the judges' decision is the final one.

"We are disappointed, but we respect it."

Canada won a 3,000m relay medal for the seventh successive Winter Games.

China's Fan Kexin, Li, Liu Qiuhong and Zhou Yang were disqualified after Zhou pushed her teammate during an exchange and then lingered on the track too long, forcing a Korean skater to go around her.

Fan was supposed to skate the last lap instead of Li, but Fan wasn't ready and Li had to exchange. After passing Li to take the lead, Shim easily outsprinted her Chinese rival to the finish. "Our team is united, but we made mistakes this time," Fan said.

Even retired eight-time Olympic short track medalist Apolo Anton Ohno was stunned by the chaos that is typical in short track.

"I can't believe that," he said. "That was crazy."

Liu had earlier been disqualified in her 1,000 heat.

In the men's 500, Viktor Ahn of Russia easily advanced to the quarterfinals, putting him in position to become the first skater to win an Olympic gold medal in all four individual short track events.

The South Korea-born Ahn made it safely through his heat. He won his adopted country's first gold in the capricious sport in the 1,000, and earned a bronze in the 1,500.

Ahn became a Russian citizen in 2011, after winning three gold medals for South Korea at the 2006 Winter Games.

Elsewhere, Slovenian alpine skier Tina Maze bagged her second title after snaring the downhill gold by edging Austrian arch-rival Anna Fenninger by a hairsbreadth seven-hundredths of a second in the giant slalom.

The Slovenian skier is the first woman since Marie-Theres Nadig of Switzerland at the 1972 Sapporo Games with enough versatility to master the downhill's test of pure speed and the giant slalom's more technical turns at the same Olympics.