Kim Jin-gyu scored a last-gasp extra-time winner to send Jeonbuk Hyundai Motors into the Asian Champions League quarter-finals after a 2-1 win over fellow South Koreans Daegu FC on Thursday.

Substitute Kim bundled the ball home in the 121st minute to secure a hard-fought victory for two-time champions Jeonbuk with penalties looming.

The game kicked off the East region's knock-out round, with all matches being played in the Japanese city of Saitama and decided over one leg.

Song Min-kyu gave Jeonbuk the lead at the start of the second half only for Brazilian Zeca to level for Daegu 10 minutes later with his seventh goal of the competition.

Daegu went into the match in disarray, with manager Choi Won-kwon stepping in to replace Alexandre Gama after the Brazilian quit just days earlier following a poor run of results.

Both sides toiled in an uneventful first half but the game exploded into life 40 seconds into the second period.

Jeonbuk winger Han Kyo-won turned the Daegu defence inside out before delivering a cross that Song lashed home with a low volley.

Zeca levelled against the run of play for Daegu 10 minutes later, getting between Jeonbuk's defenders to latch onto a through-ball and rifle into the net.

Daegu had chances to win the game within 90 minutes and Jeonbuk's Lee Seung-gi rattled the post once extra time was under way.

Jeonbuk captain Kim Jin-su also hit the woodwork but Kim Jin-gyu finally managed to find the target in extra time injury time.