Qatar's Al Sadd overcame Suwon Bluewings 2-1 on aggregate despite losing the second leg of their semi-final 1-0 at home.
Jeonbuk qualified 5-3 on aggregate and the South Koreans will be confident of a second title following their 2006 success after another high-tempo attacking display saw off the Saudis.
"We got what we wanted, we are at home for the final and that is an advantage," Jeonbuk coach Choi Kang-hee told reporters. "Eninho's goals were a big help but we still had work to do."
Al-Ittihad's slim hopes of overturning the 3-2 first leg deficit at the World Cup stadium in Jeonju suffered an early blow when their leading striker Naif Hazazi was shown a red card in the 12th minute for head-butting Cho Sung-hwan.
Hazazi, who scored his side's two goals in the first leg, shoved a team-mate after the referee waved the red card, before collapsing to his knees in tears. Two other Saudi players had to help him from the field.
"The sending-off was another blow but there won't be any punishment for Hazazi. He is an excellent player and this kind of thing happens in football," Al-Ittihad coach Dimitri Davidovic said.
Ten minutes later Eninho raced on to a neat flicked header from Jeong Shung-hoon, held off a heavy challenge and struck a left-foot shot into the corner from 14 metres out.
Jeonbuk flowed forward with wave after wave of attacks before Eninho scored a deserved second in the 36th minute direct from a corner. The Brazilian's inswinger went over Rashed Al Rahab at the near post and sneaked past goalkeeper Mabrouk Zaid.
DICTATED PLAY
The Saudis, who won back-to-back Champions League titles from 2004, pushed forward bravely in the second half and grabbed a consolation goal in the 73rd minute through Brazilian Wendel after a clever pass by Mohammed Noor.
The night ended badly for Jeonbuk when, with two minutes left, substitute Krunoslav Lovrek was sent off after collecting a harsh second yellow for tangling with Al Rahab after play had stopped.
The red card means he will miss the final along with striker Luiz Henrique and defender Cho Sung-Hwan, who picked up yellow cards and will be suspended.
In Doha, South Korea's Suwon sparked hopes of an unlikely turnround by taking the lead after just seven minutes at the air-conditioned Al Sadd stadium with a superb volley by Oh Jang-eun.
The Suwon striker controlled the ball on his chest before firing a low right-foot shot into the corner to halve the 2-0 deficit from the controversial first leg.
Al Sadd were missing attacking duo Keita Kader and Mamadou Niang after they were red-carded after a 22-man brawl in the first leg, and the Qataris opted to drop deep to protect their lead.
The visitors dictated play and enjoyed the bulk of possession against their more physical opponents but failed to create the clear-cut chances their dominance merited.
Al Sadd's former Asian Player of the Year Khalfan Ibrahim was impressive th
