Jeong, a 21-year-old ranked 105th competing in his first world championships, showed no fear against the 19th-ranked Artamonov in an action-packed contest.

Jeong built a quick 7-2 lead in the first of the three two-minute rounds powered by a three-point kick to the head. Artamonov quickly pulled into a tie, before Jeong closed out the round with a two-point kick.

Jeong kept on going, picking up six unanswered points to open the second round. Artamonov got four points back but still trailed 17-11.

Down 20-14 early in the third, the Russian refused to go away. He got to within 22-20 with about 30 seconds left, as the partisan home spectators got to the edge of their seats.

Jeong gave himself some breathing room with a two-point kick, but then committed three consecutive "gam-jeoms," or deduction penalties, as the lead was whittled down to 24-23. Artamonov tried desperately to get at least a tie and force an extra round, but the South Korean survived the nervy final moments.

Jeong said he was happy that his hard work over the past three months paid off with the gold medal.

"I really don't have much experience internationally, and in the few that I went to last year, I didn't do so well," he said. "This week, I wanted to make sure I had no regrets. I don't really believe people when they say something feels like a dream, but this victory does feel like a dream."

In the semifinals earlier Wednesday, Jeong upset world No. 1 Carlos Navarro of Mexico 15-3.

The 23rd edition of the world championships ends on Friday. (Yonhap)