Ulsan had not won away in the competition in more than two years but put in an assured performance at Saitama Stadium and, after falling behind, leveled before the interval through Joo Min-kyu before substitute Hwang Il-su struck a late winner. 

The victory means the Korean side now must only avoid defeat at home – where they have won all three of their games to date – to progress to the quarter-finals for the first time since winning the competition in 2012.

The club from Korea Republic fought back from going a goal behind to take the win and, in the process, secure a pair of vital away goals ahead of the return meeting at Ulsan Minsu Stadium in seven days’ time.

Hwang Il-su came off the bench to bury a late winner to hand Ulsan not only the win but two crucial away goals ahead of next week’s tie in Korea Republic. Kenyu Sugimoto opened his AFC Champions League account in the first half before Joo Min-kyu restored parity ahead of the intermission.

The game pitted the two former winners of the tournament against one another for the first time in the AFC Champions League, which could be considered surprising given the frequent appearance of the clubs on this stage.

The 24-year-old had been out of action in recent weeks, missing China PR’s games against the Philippines and Tajikistan, but returned for the 2-0 victory over Shanghai SIPG on Friday and then played a crucial role in the win over domestic rivals Shandong in the 2019 AFC Champions League.

Having missed a gilt-edged opportunity early in the game, Wei put the two-time winners in front in the 35th minute and was then quick to show his appreciation to doctor Silvano Cotti, running straight to the bench to embrace the Italian.

Sanfrecce had entered the tie at Kashima Soccer Stadium on the back of a five-match winning run in the Continental tournament, but on 24 minutes the hosts' Brazilian star Serginho rediscovered his golden touch at this phase of the competition to net his sixth goal in seven knockout stage appearances.

The away side responded to going behind and would ultimately dominate possesion (60 percent to 40 percent) as well as have more efforts on goal than their hosts in the match, but they were unable to make their chances count.

The late sending off of midfielder Sho Inagaki also compounded matters on a difficult night for Morishima and his teammates.

The two teams shared the spoils in the first leg in Shanghai in their previous meeting in the knockout rounds of the competition – then it was the quarter-finals – in 2016 before Jeonbuk went on to hand the Chinese Super League side a 5-0 thrashing before going on to eventually win the title.

But Morais, who replaced long-term coach Choi Hang-hee at the start of the season, was refusing to take any cues from the past after seeing SIPG’s Wang Shenchao cancel out Moon Seon-min’s first minute opener to leave the tie delicately poised.