Brazilian Leonardo opened the floodgates in the 52nd minute when he curled in a left-footer from the edge of the box after a brilliant build-up by the hosts, who are on course for their third straight K-League title.
Six minutes later, Shi Ke scored an own goal for last year's Chinese Super League runners-up when he poked the ball home trying to make a clearance with Leonardo lurking close.
The Chinese side, who held Jeonbuk 0-0 in the first leg at home in August, had Lu Wenjun sent off in the 74th minute and the hosts made full use of their numerical advantage to pump three more goals in.
Leonardo converted a penalty in the 83rd minute before substitute Lee, the 37-year-old South Korean striker, added two more goals to make it 5-0 for the hosts, who will make their first ACL semi-final appearance since 2011.
In the last four, Jeonbuk will meet the winner of the quarter-final clash between FC Seoul and Shandong Luneng.
In the day's other quarter-final, 2003 champions Al Ain sealed their second semi-final appearance in three seasons with a 1-0 win over Lokomotiv Tashkent.
After a goalless first leg, Al Ain's Caio Lucas Fernandes scored the only goal of the match seven minutes before the break with a strike from the centre of the penalty area and the club survived a second-half Lokomotiv fightback.
Al Ain will face the winner of the quarter-final clash between Al Nasr and El Jaish later this month.
(Reporting by Sudipto Ganguly and Ian Rodricks; editing by Pritha Sarkar)
