Former French Ligue 1 striker Jo-Gook Jung scored the winner in the 37th minute as the capital-based club claimed their fifth K-League title.

The victory over Jeju gave FC Seoul an unassailable 12-point lead over Jeonbuk Motors with three games to play.

Earlier, Jeonbuk missed an opportunity to put pressure on FC Seoul, drawing 3-3 at home against Ulsan Hyundai.

Ulsan midfielder Chang-Hyeon Ko put the visitors ahead in the 28th minute before former Middlesbrough striker Lee Dong-Gook equalised three minutes later.

However, Brazilian striker Maranhao undid the home side's good work, scoring twice just before half time to give Ulsan a 3-1 lead.

Jeonbuk still managed to get something from the game as they fought back in the second half to grab a draw with Dong-Gook converting a penalty in the 69th minute and Eninho equalising eight minutes from time.

In other Championship round games, Busan I'Park and Pohang Steelers shared the spoils 1-1 after Ji-Ho Han's seventh minute strike for Busan was cancelled out by Jin-Sung Hwan in the 16th minute.

Gyeongnam and Suwon Bluewings played out a 0-0 draw.

In the Relegation round, Gangwon remained one point behind Gwangju in the drop zone with a 3-2 loss against the Chunnam Dragons.

Cha-Won Ko and Suk-Young Yoon gave Chunnam a dream start in the first 11 minutes before Weslley pulled one back from the penalty spot for the home side on 20 minutes.

Striker Dong-Woon Sim iced the game for Chunnam on 87 minutes and Myung-Jung Kim scored a consolation goal for Gangwon in stoppage time.

Daegu claimed a 2-0 win at Seongnam with strikes by Jae-Hoon Ahn and Il-Soo Hwang sealing victory.

Gwangju missed a chance to extend the gap on Gangwon with a second-half equaliser from Hang-Seok Noh cancelling out Jun-Jae Nam's opener for Incheon United in a 1-1 draw.