BEIJING -- The 2018 Olympic men's skeleton champion Yun Sung-bin ranked outside the top 10 halfway through his gold medal defense at Beijing 2022 on Thursday.

The South Korean had a combined time of 2:02.43 to rank 12th after the first two of four runs at Yanqing National Sliding Centre in Yanqing District, northwest of Beijing. Yun sits 2.10 seconds back of the leader, Christopher Grotheer of Germany.

The one other South Korean in action, Jung Seung-gi, is in 10th place at 2:02.22.

At PyeongChang 2018, Yun became the first South Korean to win an Olympic sliding gold medal. But Yun is in the midst of his worst season since that Olympics, and he will have to make up substantial ground to sniff a medal this time around.

Yun finished his first run in 1:01.26 and improved that time by 0.09 second in the next run.

Jung, who won his first career International Bobsleigh & Skeleton Federation (IBSF) World Cup medal in December, posted 1:01.18 in his first slide. He was faster by 0.14 second in the next run.

In 2018, Yun capitalized on the opportunity to train extensively at the Olympic venue as the slider for the host country. For Beijing 2022, Chinese sliders were expected to enjoy a similar advantage.

One Chinese, Yan Wengang, is in third place at the halfway point at 2:01.08, 0.05 behind the second-place slider from Germany, Axel Jungk. Another slider from the home country, Yin Zheng, is seventh.

The third and the fourth run are scheduled for Friday.