Jeonbuk, winners in 2006 and 2016, needed extra-time for the second game in a row to advance with Modou Barrow, Gustavo and Moon Seon-min on target in a 3-1 win over Japanese side Kobe.
Kobe had impressed during their win against J1 League leaders Yokohama F Marinos in the last 16 and took the lead in the 64th minute through Koya Yukuri.
Jeonbuk never cleared Yuki Kobayashi's corner and, after Gotoko Sakai saw his low shot saved by Jeonbuk goalkeeper Lee Bum-soo, Yukuri pounced on the rebound to clip the ball home.
Kobe's lead only lasted two minutes. Gustavo, on as a halftime substitute, released Barrow behind the Japanese side's defence and he raced in to slot the ball through the legs of goalkeeper Daiya Maekawa.
That ensured the game went into extra time and Barrow turned from scorer to provider in the 104th minute, sending his cross over from the left for Gustavo to power his header home.
Moon put the seal on the win in injury time.
Urawa Reds - Pathum United 4-0
Two-time winners Urawa, meanwhile, pummelled BG Pathum United 4-0 to secure a fifth Asian Champions League semi-final appearance.
Urawa saw efforts from Yusuke Matsuo and Takahiro Sekine ruled out for infringements before David Moberg Karlsson gave Ricardo Rodriguez's side a 32nd minute lead with a low strike that goalkeeper Kittipong Phoothawncheuk was unable to keep out.
Ten minutes later the Japanese side were further ahead as Takuya Iwanami found just enough space to rise up and glance Ken Iwao's corner beyond Kittipong.
Yosho Koizumi hit Urawa's third in the 65th minute when he slotted in following Atsuki Ito's pass along the edge of the penalty area while Takahiro Akimoto fired into the top corner seven minutes later to claim his side's fourth.
The winner of Thursday's semi-final will take on the leading club from west Asia in the final.
Teams in the west will play their knockout fixtures in February with the final held over on a home-and-away basis on February 19th and 26th.
