Reigning champions Pohang Steelers lost ground to Jeonbuk Motors at the top of the K-League standings after slumping to a 2-1 defeat at the hands of Branko Babic's Gyeongnam FC.
Go Moo-yul thought he had earned a point for Pohang when his 84th-minute goal cancelled out Lee Jae-an's 65th-minute strike, but Lee Chang-min netted in the final minute to earn a much-needed win for Gyeongnam.
Jeonbuk stretched their lead at the summit to five points with a 2-0 triumph against Jeju United, with Kim Dong-chan and star striker Lee Dong-gook slotting home in the first six minutes of the game.
Elsewhere, a second-half strike by Kim Dong-sub gave Seongnam Ilhwa Chunma FC a 1-0 victory over Chunnam Dragons.
Busan I'Park and Sangju Sangmu Phoenix drew 1-1, as did Suwon Bluewings and Incheon United.