Ulsan wasted an opportunity to move to the summit of the K-League as they were held to a 0-0 draw by Suwon Bluewings on Sunday.
Kim Ho-Gon’s side could have leapfrogged Pohang Steelers at the top with a win, but failed to break through a resilient Bluewings back line and remain in second as a result.
Pohang’s grip on top spot was weakened by their 2-0 home defeat to Jeonbuk Motors 24 hours earlier – their second loss in three games.
Park Hee-Do kicked things off for Jeonbuk with just five minutes on the clock, and former Pohang forward Lee Dong-Gook completed the scoring with ten minutes gone to help his side up to fifth.
There was also movement below the top two over the weekend, with Jeju United jumping into third place courtesy of a 4-2 win over Gyeongnam.
A hat-trick from Pedro Junior guaranteed the points for Jeju, and ensured they would move ahead of Incheon United in the standings.
Incheon could only draw 1-1 with Chunnam Dragons on Saturday, as an 83rd-minute strike from Park Jun-Tae pinched a point for the hosts.
At the bottom of the K-League, two 0-0 draws ensured the status quo would be maintained in the battle against the drop.
Daegu, who currently sit 13th, were held at home by 12th-placed Gangwon, while rock-bottom Daejeon CItizen remain three points behind them after taking the same result from their home clash with Busan I’Park.
Elsewhere, ninth-placed Seoul moved two points short of Seongnam with a convincing 3-0 victory over An Ik-Soo’s men.