China's flying start to its home Winter Olympics hit a bottleneck on Wednesday when star short-track speed skater Ren Ziwei was disqualified from the men's 1,500 meters.

However, China's snowboarders' strong runs in the women's halfpipe raised hopes that more medals are on the way.

After winning two gold medals in three days, Ren had to deal with major disappointment on Wednesday night after receiving a penalty for an arm block approaching the finishing line in his 1,500m semifinal. He was disqualified from competing in the final, his strongest short track event.

Ren, who topped the rankings during the World Cup season, conceded he sprinted too hard, which caused the illegal contact. "I expected too much from this race, so I made a stupid mistake," said Ren, who helped China win its first gold in the mixed team relay on Saturday before claiming his first individual Olympic title in the men's 1,000m two days later.

"For my next events (the 500m and 5,000m relay), I feel relaxed now that I've won two golds, and I will approach it one race at a time, feeling free of pressure," said the 24-year-old from Heilongjiang province.

South Korean skater Hwang Dae-heon won the gold. He burst to the lead after a congested start and crossed the line first in a time of 2 minutes 9.219 seconds. Canadian Steven Dubois finished second and Semen Elistratov of the Russian Olympic Committee took the bronze medal.

Earlier, China's snowboarders performed well at Beijing's co-host Zhangjiakou, Hebei province. In the women's halfpipe event, snowboarders Cai Xuetong, Liu Jiayu and Qiu Leng all qualified for Thursday's final after each of them completed at least one solid run in the two-run preliminary round. A competitor's highest score counts for their ranking.

Cai and Liu are both competing at their fourth Winter Olympics and are considered among the best riders in the event, which features spectacular aerial tricks launched from a ramp. The Chinese qualifiers will face Olympic champion Chloe Kim of United States in the final.

"I still feel as fresh as my first Olympics. I'm very excited and eager to enjoy the competition," said Cai, a two-time world champion. "Whether I make it or not, I will increase the degree of difficulty in my routine in the final."

Liu, who won silver behind Kim at the 2018 Pyeongchang Winter Games in South Korea, overcame an early scare after crashing midway through her first run. However, she secured her spot in the final with a safe second run.

"It's such an honor to compete here, but at the same time it's just another contest. No matter how big an event or where it is, I am a snowboarder and I just snowboard," Liu said of her mindset going into the final.

Meanwhile, legendary US snowboarder Shaun White overcame a first-run fall to reach an Olympic final in the men's halfpipe for the fifth time after finishing his second qualification run in style.

The 35-year-old will be aiming for a record fourth gold medal in the event. Japan's Hirona brothers, Ayumu and Ruka, as well as Australian rider Scotty James are expected to join the battle for gold in Friday's final.