New signing Hernandez gave the two-times winners the lead 17 minutes into the game and Ahn Hyun-beom doubled that advantage in the 64th minute to put Jeonbuk in control of the tie ahead of the second leg at the Pohang Steel Yard next Wednesday.

Jeonbuk, looking to reach the last eight of the competition for an 11th time since 2004, dominated the early exchanges and it came as little surprise when the 2006 and 2016 champions took the lead.

Hong Jeong-ho hit the crossbar with his strike from distance and, while the ball was partially cleared, the Pohang defence was never convincing in their efforts to keep out Jeonbuk.

Eventually, the ball fell at the feet of Hernandes after Kim Jin-su’s centre from the left and the striker controlled the ball in the penalty area with his first touch before thumping a shot on the turn past Hwang In-jae via the underside of the crossbar.

Pohang survived a penalty scare midway through the first half when Jonathan Aspropotamitis and Tiago Orobo tangled in the area and referee Shaun Evans consulted the pitch-side monitor before deciding not to punish Park Tae-ha’s visitors.

Orobo then forced Hwang In-jae into a last-ditch block when he burst through the Pohang defence in the 31st minute while Lee Yeong-jae bent a free kick narrowly wide and Lee Dong-jun saw his deflected long-range strike saved by the Pohang goalkeeper.

Jorge Luiz led Pohang’s fightback after the interval, forcing Kim Jeong-hoon into an early save to his right after a strike from outside the area while hitting the side netting in the 55th minute after spinning past the Jeonbuk defence. He then sent a diving header wide.

Jeonbuk, though, remained dangerous on the break. Orobo released Ahn Hyun-beom with a perfectly-timed through ball in the 63rd minute and, although Lee Dong-jun shot wide after being fed by his team mate, the two-times champions doubled their lead a minute later.

Ahn made no mistake as emerged through the Pohang defence to throw himself at Kim Tae-hwan’s cross from the right to head past Kim Jeong-hoon and give his side a more comfortable cushion ahead of the second leg.