Jeonbuk face Cerezo Osaka in the second-leg of their Asian Champions League quarter-final on Tuesday but will have to raise their game against a Japanese team they trail 4-3 on aggregate, although coach Choi Kang-hee did rest a number of first-team players for this clash.
Jeju had the better of the chances with Kim Eun-jung and Santos coming close as Jeonbuk were unable to create many clear openings.
"That was a very tough game," said Choi.
"It is the first time we have played in the afternoon for a long time and our physical and concentration levels dropped.
"Now we can think about Cerezo Osaka, it should be a very good game and one that we can win."
FC Seoul, looking to overcome a 3-1 deficit against Al Ittihad of Saudi Arabia on Tuesday, had no such problems in defeating Daejeon Citizen 4-1 thanks to a hat-trick from in-form striker Dejan Damjanovic.
The Montenegrin marksman grabbed two early goals and although Lee Sang-hyob hauled the visitors back into the game midway through the second-half, Damjanovic restored Seoul's two goal advantage almost immediately. Mauricio Molina added a late fourth.
Suwon Bluewings travel to Zob Ahan for the second leg of their quarter-final with a 2-1 win at Daegu FC under their belts. Yeom Ki-hyun scored in the first-half and Lee Sang-ho in the second with Kim Min-gu grabbing a late consolation for the hosts.
Finally, second-half efforts from Seol Ki-hyun and Park Sung-il gave Ulsan Horangi a 2-0 win at Incheon United while Gangwon FC drew 0-0 at Gyeongnam.