Four former continental champions are still in the mix, alongside a side with a 100 percent record, a tournament debutant, a 2017 semi-finalist and a Japanese giant as the competition promises to serve up yet more thrilling action over the second half of the year.

When the AFC Champions League wheels resume turning with the last eight, some teams will have a new look, with new managers and players joining over the summer, while for others, stability is the key weapon as they pursue continental glory.

Jeonbuk’s Lee Dong-gook and Suwon’s Dejan Damjanovic are the two leading scorers in AFC Champions League history with 36 and 32 goals respectively, since the 2002-03 revamp.

And, although with a combined age of 76, they still remain among the goals in the 2018 campaign.

For the first time since the introduction of the East v West final in 2013, all four teams in the West Asian quarter-finals come from just two countries, offering us the opportunity to watch two tasty IR Iran v Qatar encounters, as Tehran giants Estaghlal and Persepolis face Al Sadd and Al Duhail respectively.

Throughout the years, teams from the two nations have produced some classics when they met. Here are four memorable matches between them from recent editions of the competition.

Debut strikes, stunning volleys and smart chips, the AFC Champions League quarter-finals has produced some memorable goals throughout the years. Here we recall some of the best goals scored at this stage of the competition, hoping this year's edition will deliver more of the same.

Domestic rivalries add a new dimension to the AFC Champions League, and throughout the years we have enjoyed some classic at the quarter-final stage. Heroic comebacks, nervy draws and closely fought contests were all present. Interestingly, never have two West Asian sides from the same country met in the competition's quarter-finals. So, here are four times rivals clashed in the last eight in recent years.

Having won an incredible four UEFA Champions League titles with Barcelona as part of what was arguably the greatest club side to ever play the game, Spanish midfielder Xavi Hernandez was a huge coup for Al Sadd when he joined in 2015.