It has been neck-and-neck at the summit in South Korea's top-tier football competition but Jeonbuk's 2-0 win at second-placed Pohang Steelers in round 21 last week created a four-point buffer for Choi Kang-hee's men.
K. League top goalscorer Dong-Gook Lee was on target in the victory - taking his season tally to 10 goals.
"It was the most important game this year," the 35-year-old striker said.
"We were able to beat Pohang because of the players' will."
Jeonbuk - the in-form team of the competition - have won four league games in succession, keeping three clean sheets in the process.
Factoring in draws, Jeonbuk are in the midst of a 10-match unbeaten streak and another win, coincided with a loss for Pohang at cellar-dwellers Gyeongnam, could see the club move seven points clear in the race for the championship.
However, Saturday's meeting at Jeonju World Cup Stadium presents a tricky challenge for Jeonbuk.
A total of 16 points separates Jeonbuk and Seoul in 2014, but the capital club have the edge over the league's high-flyers when it comes to recent encounters.
Jeonbuk have only won one of the past 12 games between the two teams since 2010, with Seoul winning five, while there have been six draws.
Gyeongnam and Pohang kick-off at the same time on Saturday, and the visiting team will be undoubtedly eager for a response following their defeat to Jeonbuk.
Though, fitness could be a cause for concern for Pohang at Changwon Football Center, having contested the first leg of their AFC Champions League quarter-final fixture on Wednesday.
Pohang played out a scoreless draw with rivals Seoul in an all-Korean affair.
In Saturday's only other fixture, Ulsan - sixth in the standings - welcome Sangju Sangmu to Munsu Cup Stadium.
After back-to-back wins, Ulsan were beaten by fourth-placed Jeju United as they lost ground in the championship race.
On Sunday, Jeju United are in action at Incheon United.
Third-placed Suwon Bluewings play host to second-bottom Seongnam, who have lost three in a row.
Meanwhile, Busan I'Park and Chunnam Dragons go head-to-head at Busan Asiad Main Stadium.