Jeong’s 76th minute goal cancelled out Park Chan-yong’s opener from the 12th minute for Pohang as two-time champions Jeonbuk banished any concerns they would throw away their hard-earned 2-0 first leg advantage.

Petrescu and his team will next face either compatriots Ulsan Hyundai or Japan’s Ventforet Kofu in the last eight, with Hong Myung-bo’s K League 1 champions holding a 3-0 first leg advantage going into Wednesday’s second leg.

Jeonbuk went into the game holding a solid advantage and looked the more threatening in the opening exchanges, with Pohang goalkeeper Hwang In-jae punching Han Kyo-won’s early shot clear while Hong Jeong-ho looped a free header high over the bar moments later.

But Pohang pulled themselves back into the tie, Park Chan-yong hitting a right foot drive that moved slightly in the air and, with the heavy rain at the Pohang Steel Yard making conditions difficult, Kim Jeong-hoon allowed the ball to slip past him and over the line.

Jonathan Aspropotamitis then headed over the bar and Lee Ho-jae, following Park’s example, shot hard and early but his effort was narrowly wide of Kim’s right post.

At the other end, Tiago Orobo’s downward header was too firmly met by the Brazilian, the ball bouncing back up off the turf to clear the crossbar.

Pohang continued to push for a second; Jorge Luiz was denied by Kim diving to his right while Heo Yong-jun headed wide following Wanderson’s cross from the left. With seconds left in the half Kim came to the rescue again, pushing another low Heo shot wide.

Lee Ho-jae then hit the post after Jorge Luiz cut inside to lay the ball off in the final seconds of a half dominated by the hosts.

Moon Seon-min’s introduction at halftime gave Jeonbuk a much needed boost, the Korea Republic international shooting over the bar with a strike on the run eight minutes after the interval and then forcing a low save from Hwang with an astute overhead kick.

With the momentum now in their favour, Jeonbuk levelled the scores on the night and effectively confirmed their place in the next round when the Pohang defence failed to clear Tiago’s corner and Jeong rose to nod in with only 14 minutes left on the clock.