HOENGSEONG, South Korea — A determined Markku Koski soared through the air to seize the world big air title Saturday from defending champion Mathieu Crepel.

The contest on the last day of the World Snowboard Championships came down to three men: Koski, Crepel and Seppe Smits, who fought round by round for the gold.

Crepel, the bronze medalist in Friday's halfpipe competition, took an early lead by nailing a backside 1080 — a jump that entails making three full rotations in the air — for a first-round high score.

Smits launched a big frontside 1080 and landed it perfectly, putting him in second position. Koski was in third with a stylish backside 900 at the end of the first round.

But the Finn, an Olympic bronze medalist in the halfpipe at Turin in 2006, put the pressure on Crepel and Smits with a huge, tight 1080 in the second round. The judges gave the trick an event-high score that vaulted him into the overall lead.

Crepel failed to improve his best-of-two score in the second run; he caught the lip of his snowboard on the landing and went down face first. A consistent Smits, meanwhile, pulled off another clean frontside 1080, leaving him with the third-highest score behind Koski and Crepel.

Playing it conservative in the final round, Smits landed a clean backside 900 to take the lead.

With the pressure on, Crepel went for it — but put his hands down on the landing of the frontside 1080, dropping him down to sixth place and leaving room for Kospi to seize the lead.

Kospi stepped up to the challenge and nailed his jump, seizing the gold and the world title — a big improvement after finishing 16th at his last big air contest in October.

"I can't believe it," Koski said. "I've been hitting jumps all season but I only did those tricks at rehearsal today and it came together today."

Smits took home silver while Stefan Gimpl claimed the bronze by pulling off a strong frontside 1080 in the second run and a clean frontside 900 in the third round.

The competition at Hyundai Sungwoo Resort was the first Snowboard World Championships in Asia. Medals were awarded for five disciplines: snowboardcross, parallel giant slalom, parallel slalom, halfpipe and big air.