Jeonbuk Motors must overcome recent history and the K. League's form team when they tackle Seoul on Saturday.
Not only have Jeonbuk beaten Seoul just once in their previous 12 encounters in all competitions, but their Round 27 visitors are undefeated in 11 matches.
Seoul are expected to field a weakened team ahead of the second leg of their AFC Champions League semi-final – something league-leading goalscorer Lee Dong-Gook (12 goals) will try to exploit for Jeonbuk.
Pohang Steelers, one point behind Jeonbuk, have only managed four goals in their past eight games.
They are up against third-placed Suwon Bluewings, for whom in-form goalkeeper Jung Sung-Ryong will attempt to frustrate the club at which he started his career.
A Suwon win would leave them three points behind second-placed Pohang.
Jeju United, one point behind Suwon in the fight for the final Champions League qualifying place, are away at struggling Seongnam on Sunday.
Seven-time K. League champions Seongnam are just two points above the relegation play-off place, and desperately require a return to form from Uzbekistan playmaker Server Djeparov.
Busan I'Park, the team directly beneath Seongnam, are away to mid-table Jeonnam Dragons, while cellar-dwellers Gyeongnam host Sangju Sangmu.