South Korean challengers looming as dominant force in 2021 AFC Champions League

As the AFC Champions League East Zone group stage came to a close on Sunday, Daegu became the final team through to the knockout stages as their 4-0 defeat of United City confirmed that all four South Korean sides remain in contention for the continental crown.

With seven of the eight teams having already booked their Round of 16 berths ahead of the final day of action, the only things left to decide were Daegu's fate in the competition, and the winner of Group F that was a straight scrap between reigning champions Ulsan Hyundai and BG Pathum United.

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Daegu got the business done with an easy win over tournament debutants United City FC in Group I while compatriots Ulsan secured top spot in their group by overcoming Pathum United. The Thai League 1 champions also progressed as one of the best second-placed teams.

Daegu and Ulsan will be joined by their K League 1 rivals Jeonbuk Hyundai Motors and Pohang Steelers in the last 16. Pathum United and the Japanese trio of Nagoya Grampus, Kawasaki Frontale and Cerezo Osaka complete the lineup from the East.

It was in 2015 when the Round of 16 last featured four South Korean contenders. All four progressed as the runners-up from their respective groups as China's Guangzhou went on to emerge as Asian champions by overcoming Shabab Al Ahli of United Arab Emirates in the final.

With no Chinese Super League sides in the knockout stages this time around, the 2021 edition provides a opportunity for an easier shot at the continental title. And it looks like the sides from the Korea Republic are raring to make full use of it.

Ulsan will again be the frontrunners as they mount a title defence after winning all six of their group stage games from a pool featuring Pathum United, Viettel and Kaya FC-Iloilo. Despite losing their ACL-winning coach Kim Do-hoon and last season's top scorer Junior Negrao, Ulsan are still in red-hot form as they also leading their domestic K League 1.

South Korean champions Jeonbuk also look among the favourites from the East this term as they look to overcome the disappointment of a group-stage exit last year. The 2016 Champions League winners are powered by two of the hottest forwards in the continent at the moment with Gustavo and Modou Barrow netting a whopping 13 goals in the group stages.

Daegu, who progressed as one of the three runners-up, also boast of a prolific strike partnership featuring Brazilian duo Cesinha and Edgar Silva, who have been on fire in Asia and also closer to home. But two losses to Japan's Kawasaki twice Group I does suggest they will have to step up come September to progress deeper.

The same can be said of three-time Asian champions Pohang, who not only lost to Group G winners Nagoya but also were held to a goalless draw by Thailand's Ratchaburi Mitr Phol. Kim Gi-dong will hope to fix their difficulties in front of goal that were evident in their last two group games as they missed chance after chance.

In the single-legged Round of 16 ties slated for September, Daegu will face Nagoya while Pohang take on Cerezo. First-timers Pathum United will be up against Jeonbuk while Kawasaki will stand in Ulsan's way as the Tigers look to defend their continental crown.

It is unlikely but not impossible that all four K League 1 sides could end up moving on into the quarterfinals.

Now that would be some way to assert South Korean's dominance on the 2021 AFC Champions League.