The Pohang Steelers defeated Ulsan 1-0 in the K-League on Saturday to move up to fourth in the championship round with four games to play.
Byung-Jun No scored the only goal of the game in the 68th minute at the Munsu Cup Stadium but the Steelers are still 15 points behind leaders Seoul.
Jeju United defeated Gyeongnam 2-0 with goals from Brazilian duo Jair and Santos Junior.
Leaders Seoul are in action on Sunday and hold a seven-point lead at the top of the league with five games to play.
In the relegation round, Incheon United extended their undefeated run to 13 games with a 2-1 victory at Seongnam.
They lead the relegation table by eight points with Gwangju's clash with relegated Sangju Sangmu called off due to the latter side's refusal to play their remainder of their games.