As the game headed for a goalless draw, Chunnam faced crashing out of the competition until the substitute fired home to condemn Chonburi FC to their first defeat of the campaign.

In heavy rain and fierce wind, Chonburi could have taken an early lead when Dragons goalkeeper Yeom Dong-hyun flapped at a free-kick and Natatorn Phanrit inexplicably headed the easy chance wide at the far post.

After the early warning, Chunnam, who are bottom of the K-League after four games, had their first real chance in the 16th minute when Kim Myung-woon received a long ball on the edge of the area, turned and shot straight at keeper Kosin Hathairattanakool.

Lee Kyu-ro then smashed over from 10 yards after Yoo Hong-youl had nodded Kim Chi-woo's cross back across goal as Chonburi soaked up the pressure.

The visitors had a great chance after half an hour when Ekaphan Inthasen volleyed a loose ball goalbound but Dong-hyun saved well.

The Dragons could have gone into the break in the ascendancy but Lee's shot from close range was pushed on the inside of the right post by Hathairattanakool before the ball was cleared to safety.

Chonburi wasted a good chance just after the restart when Ekaphan was sent clear, the striker choosing to pass instead of shooting and the chance elapsed.

Song Jung-hyun hit the side-netting in the final 20 minutes and the game looked to be heading for a stalemate. But Victor stepped up to take a free-kick just outside the area and curled a superb shot into the top right corner.