Suwon Bluewings moved into third in the K-League with a 1-0 win over leaders Seoul but second-placed Jeonbuk did not take full advantage.
Oh Jang-Eun’s 52nd-minute strike gave Suwon the win at home over Seoul, handing the K-League leaders their first defeat in six matches.
Suwon have overhauled Ulsan thanks to Wednesday’s result and taken third spot in the K-League standings with 59 points.
Seoul remain top of the title-deciding Championship Round on 73 points with 10 games remaining but Jeonbuk Motors missed the opportunity to move within two points of the leaders after a 2-2 draw away to Busan I’Park.
Jeonbuk had to come from behind twice to snatch a draw with Busan going ahead via a penalty from Bang Seung-Hwan in the sixth minute.
Lee Dong-Gook converted a penalty for Jeonbuk in the 21st minute but Busan were ahead again 10 minutes later thanks to a goal from Han Ji-Ho.
But Jeonbuk managed to take a share of the points thanks to Eninho’s equaliser with 10 minutes to play.
In the other match in the Championship Round, eighth-placed Gyeongnam played out a scoreless draw with seventh-placed Jeju United.
In the Relegation Round, Gwangju grabbed a crucial point at home with a 1-1 draw with Daejon Citizen.
Gwangju have 30 points, three ahead of bottom club Sangju Sangmu, who sit in the relegation berth.
Incheon United defeated Daegu 2-1 and Chunnam Dragons and Gangwon played out a goalless draw.