Moon Seon-min struck inside a minute in China to give two-time champions Jeonbuk a vital away goal but the Korean side were pegged back through Weng Shenchao’s equaliser shortly before the interval.

Hosts Jeonbuk have the slightest of advantages as they start the second leg at Jeonju World Cup Stadium knowing that a scoreless draw would see them progress to the quarter-finals for a ninth time.

The K league side are also unbeaten at home in the 2019 competition while Shanghai have yet to win on the road, although the Chinese champions have secured 2-2 and 3-3 draws away from home – results that would ensure they advance.

The Chinese Super League champions could not have asked for a worse start in their tie with Continental heavyweights Jeonbuk, conceding in the opening minute after Moon Seon-min's clever finish.

However, the hosts responded with Wang heading home Yu Hai's cross six minutes before half-time. Chances came and went after the interval but a 1-1 draw was to be the final scoreline. A result that Wang feels, while fair, does put his side in a difficult position going into the second leg on Wednesday.

The first leg of the Round of 16 pitted the champions of China PR and Korea Republic against each other and it took Moon less than a minute to open the scoring and silence the home support inside Shanghai Stadium.

With the outside of his right foot, Lim clipped a pinpoint delivery over the top of the Shanghai defence which Moon latched onto before lifting the ball over Yan Junling to break the deadlock before carrying out one of the more unique celebrations the competition has seen this season.

All four of the last 16 ties are tantilisingly poised - either level or with a team holding a slim one goal advantage - and promise some rollercoaster action to come. The-AFC.com has picked out five things to look out for ahead of the games.

A first half strike from Wei Shihao and an own goal from Shandong defender Zheng Zheng sees Fabio Cannavaro's Guangzhou with a slim advantage ahead of the tie at Jinan Olympic Sports Center.

However, Zhang Chi's reply for Shandong does keep theings tantalisingly poised with the Jinan side returning to eastern China with an away goal from last week's visit to Tianhe Stadium.

Despite twice reaching the quarter-finals of the AFC Champions League, Shandong have still never managed a single victory in the knockout stages, drawing four and losing three of their seven games at this stage to date.

A week ago, Kashima snapped Sanfrecce's run of five consecutive AFC Champions League victories and the visitors come into the tie looking to progress to their third appearance in the quarter-finals.

A Serginho goal in the first leg was the difference for the 2018 winners, and it was a return to the kind of form the Brazilian showed in last year's campaign as the forward netted his sixth goal in seven knockout stage ties.

Sanfrecce, meanwhile, are looking to advance to the quarter final stage of the AFC Champions League for the very first time and they will be relying on their impressive home form.

All four games remain tight ahead of the decisive return meetings in the coming days, before which the-AFC.com looks back at some of the numbers that caught the eye as the knockout rounds got underway.