Ulsan Hyundai FC, currently leading the top South Korean football league, will open their bid for a second straight continental title this week.

Ulsan will be among four K League 1 clubs to play a round of 16 matches at the Asian Football Confederation (AFC) Champions League on Tuesday and Wednesday.

Ulsan, the 2020 champions, will host Kawasaki Frontale at 8 p.m. Tuesday at Munsu Football Stadium in Ulsan, 415 kilometers southeast of Seoul.

Before that, Daegu FC will play Nagoya Grampus at Toyota Stadium in Nagoya, Japan, at 6 p.m.

Two more knockout matches are scheduled for Wednesday: Jeonbuk Hyundai Motors hosting BG Pathum United at 5:30 p.m. at Jeonju World Cup Stadium in Jeonju, 240 kilometers south of Seoul; and Pohang Steelers visiting Cerezo Osaka at 6 p.m. at Nagai Stadium in Osaka, Japan.

The K League 1 can send up to four clubs to the AFC Champions League each year and now has four clubs in the round of 16 for the first time since 2015.

Ulsan defeated Persepolis FC in last year's final for their second AFC Champions League crown. This year, they're leading the K League 1 with 55 points through 28 matches, and they will now try to pull off their first domestic-continental double (winning two major trophies).

By winning all six group stage matches, Ulsan extended their AFC Champions League winning streak to a record 15 matches. Ulsan owned the previous record of 11 consecutive wins, set between 2012 and 2014.

Kawasaki also won all six of their group matches and led everyone with 27 goals. Only one team has scored more goals in group stages: Kashima Antlers in 2008 with 28.

Jeonbuk are also two-time AFC champions, having most recently won in 2016. Their Brazilian forward, Gustavo, leads all players still alive in this year's tournament with seven goals, and he has three assists to boot.

Pohang have won three continental titles, but none since 2009.

And they'll have their hands full against Cerezo Osaka, which went undefeated in the group stage and led all East Asian teams with 67.2 percent possession. Pohang are winless in their past three meetings against a Japanese team.

Daegu FC are in the knockout phase for the first time. They have lost four straight matches against Japanese clubs in the AFC Champions League, while allowing nine goals and scoring only three.

Nagoya Grampus, on the other hand, have dropped only one of their past 10 games against South Korean opponents.

All knockout matches, including the final, will be one-and-done affairs, a change implemented to minimize traveling amid the coronavirus pandemic. Group matches were contested in centralized venues for the same reason.

K League clubs and others from countries such as Japan, Thailand and China are part of the East Region. The West Region features clubs from Iran, Iraq, Saudi Arabia, Qatar and Uzbekistan, among others.

The two regions will be on the opposite sides of the bracket through the semifinals. (Yonhap)