Making their first-ever quarter-final appearance, Al Nassr were hopeful of securing their first win over Qatari opponents in the competition, but had their work cut out for them by a late injury to star striker Abdelrazzaq Hamdallah.

In turn, Al Sadd needed a positive result from Riyadh to set them up for an easier task at home as they chase a second consecutive semi-final.

The two sides boast a proud tradition in Asian football, with nine continental titles and 18 appearances in the AFC Champions League knock-out stage between them. Nevertheless, Tuesday marks only the second time Al Ittihad and Al Hilal have met in the competition - the first being Al Ittihad's 3-1 win in the 2011 Round of 16.

The sides met four times in the 2017 edition, exchanging wins in the Group Stage before their meeting in the last four saw Urawa edge the semi-final 2-1 on aggregate as they went on to lift their second AFC Champions League title.

Last year, Shanghai SIPG were eliminated by a Japanese team for a second consecutive tournament when they were defeated by eventual champions Kashima Antlers, while Urawa failed to defend their title after they were unable to qualify for the 2018 competition.

Ahead of the four first legs, which take place between Monday and Wednesday, the-AFC.com has selected five things to look out for in a week that will see some of Asia's biggest club sides square off in a quartet of mouth-watering match-ups.

Taking into account only figures from teams and players still involved in the Continental competition, we’ve hand-picked some of the stats and facts that have caught the eye.

With nine Continental trophies and 23 Saudi League titles between them, Al Hilal and Al Ittihad are Saudi Arabia’s most successful teams and two of Asia’s greatest sides, but only one of them will make it to the last four of the 2019 AFC Champions League.

Al Hilal have reached the semi-finals three times in the past five years, while time has not been kind to two-time AFC Champions League winners Al Ittihad, whose last semi-final appearance dates back to 2012 when they lost to city rivals Al Ahli.

The quarter-finals were introduced in the AFC Champions League back in 2004, and since then we have witnessed some action-packed matches, particularly in recent times. the-AFC.com highlights five last eight ties that are worth reviewing and savouring.