Keen to put their shock 1-0 loss at home to lowly Daejeon Citizen firmly in the past, Jeonbuk stormed out of the blocks, taking an 18th-minute lead through Brazilian midfielder Eninho.
The score remained unchanged until South Korean international striker Lee Dong-Gook netted a 79th-minute goal to secure all three points.
Ulsan handed Seongnam a second successive defeat with a 1-0 win at the Seongnam Tancheon Sports Complex.
Seongnam, the 2009 runners-up, were on track for a share of the points before Kim Seung-Yong pounced with six minutes remaining to claim victory.
The victory saw Ulsan climb ahead of Suwon Bluewings into third position after their goalless draw at Busan I'Park.
Elsewhere on Wednesday, second-placed Seoul kept the pressure on Jeonbuk with a come-from-behind 2-1 victory over Gyeongnam.
Kim In-Han had given Gyeongnam the lead inside the opening eight minutes but second-half goals from Ha Dae-Sung and Sergio Escudero helped Seoul end the round in second spot.
And cellar dwellers Gwangju won their first game in eight attempts, prevailing 1-0 at home to Sangju Sangmu, while the match between Gangwon and Jeju United ended 1-1.