Hugo Droguett scored both goals from the home side, after 13 and 72 minutes, to keep Jeonbuk at the top of the standings.
FC Seoul climbed to second with a late 3-2 win against Gwangju FC.
The visitors went ahead after 15 minutes through Kim Dong-Sub's penalty, but goals from Dejan Damjanovic (69) and Choi Tae-Uk (72) turned things in Seoul's favour.
Park Hyun levelled matters after 84 minutes but a Damjanovic spot-kick two minutes from time snatched the points for the hosts.
Suwon Bluewings slipped out of the top two following a heavy 5-0 defeat at Pohang Steelers.
A Yang Sang-Min own goal plus further strikes from Shin Jin-Ho, Hwang Jin-Sung, Kim Dae-Ho and Ko Mu-Yeol saw Pohang home with room to spare.
Lee Keun-Ho scored the only goal as Ulsan Hyundai edged out Chunnam Dragons.