With one match remaining in the group stage, only one of the four South Korean teams in action has locked down a spot in the knockout phase of the top Asian club football competition.

Jeonbuk Hyundai Motors, Ulsan Hyundai FC, and Daegu FC of the K League 1 and Jeonnam Dragons of the K League 2 are playing in this year's Asian Football Confederation (AFC) Champions League. Through Thursday, they have all played five out of six group matches in centralized venues -- an arrangement put in place to prevent the spread of COVID-19.

From this quartet, Jeonbuk, a two-time AFC champions, have secured their place in the round of 16, following a 3-2 victory over Sydney FC in Group H on Thursday in Ho Chi Minh City.

Jeonbuk are in second place in the group with 11 points, one back of Yokohama F. Marinos, their opponent in Sunday's Group H finale.

There are 10 groups of four in this year's tournament -- Groups A to E for teams in the West Region, with countries including Qatar, Saudi Arabia, Iran and Iraq; and Groups F to J for teams in the East Region, with South Korea, Japan and China among the countries involved. The 10 group winners will earn automatic berths in the knockouts, joined by the three-best runners-up from each of the two regions.

Jeonbuk can win the group by beating Yokohama on Sunday. Even if they lose, they are guaranteed to finish as one of the top-three No. 2 seeds in the East Region.

Daegu FC sit atop Group F with 10 points. They are tied in points with Urawa Red Diamonds but Daegu hold the tiebreak edge thanks to a superior head-to-head record. Daegu routed Shandong Taishan 4-0 on Wednesday and will close out the group stage Saturday against Lion City Sailors.

All Group F matches are being played in Buriram, Thailand.

Ulsan, the 2020 AFC champions, are in second place in Group I, whose clubs have been playing in Johor Bahru, Malaysia. Ulsan defeated Kawasaki Frontale 3-2 on Wednesday to climb to 10 points. But Johor Darul Ta'zim still lead the group. They, too, have 10 points but have the tiebreak advantage over Ulsan following their 2-1 win over the Korean club on April 18. These two teams will meet in Saturday's finale with the automatic knockout berth at stake.

Jeonnam are in third place in Group G with seven points, despite beating United City 2-0 on Wednesday. Jeonnam remain four points back of the leaders, BG Pathum United, and can't catch the Thai club with just one match remaining. The best Jeonnam can hope for is to finish among the three-best runners-up in the East Region.

To do that, Jeonnam must beat BG Pathum United on Saturday in Pathum Thani, Thailand, and receive help from other teams.

The round of 16, quarterfinals and semifinals for the East Region are scheduled for August. West Region teams will play their knockout matches in February next year. The two-legged final will be played on Feb. 19 and 26, 2023.

The K League has won the most AFC club titles among all Asian leagues with 12 since the competition began in 1967. (Yonhap)