HONG KONG: Five times UEFA Champions League winner Cristiano Ronaldo will begin his quest to add another continental title to his resume on Tuesday when Saudi Arabia's Al-Nassr kick off their Asian Champions League campaign against 2020 runners-up Persepolis.

The Portuguese, who won his European titles with Manchester United and Real Madrid, and a host of other high-profile players lured to the Saudi Pro League will add significant stardust to Asia's premier club competition when it begins this week.

Al-Nassr are one of 40 clubs from 20 leagues across the confederation drawn in 10 groups to face one another from Monday, with only the winners guaranteed to advance to the knockout rounds in the quest for the top prize of US$4 million.

That sum seems inconsequential compared to the amounts spent by Saudi clubs to acquire a band of experienced talent in an effort to bolster a league already among the continent's best.

Al-Hilal, who signed Neymar from Paris Saint-Germain for 90 million euros in August, are the competition's most successful club, winning the title on four occasions and losing in the final of the most recent edition to Japan's Urawa Red Diamonds.

Coached by Portugal's Jorge Jesus, the Riyadh-based squad includes 12 players who represented Saudi Arabia at the last World Cup and have been further bolstered by the signings of Aleksandar Mitrovic, Ruben Neves and Sergej Milinkovic-Savic.

Al-Hilal kick off their campaign on Monday against Uzbekistan's Navbahor in Group D - which also features Mumbai City and Nassaji Mazandaran from Iran - and will be able to field up to six foreign recruits after regulations on overseas players were relaxed by the Asian Football Confederation.

Karim Benzema's Al-Ittihad, the reigning Saudi Pro League champions, will be looking to win their first Asian title since 2005 and launch their campaign against Uzbekistan's AGMK before facing Iran's Sepahan and Air Force from Iraq in Group C.

Saudi teams are expected the dominate the west Asian half of the draw with Japanese clubs attempting to maintain their position of pre-eminence in the east.

Urawa travel to meet Chinese champions Wuhan Three Towns in their Group J opener on Wednesday having also been drawn with Pohang Steelers and Hanoi FC while J.League title holders Yokohama F Marinos start their campaign against Incheon United.

Kawasaki Frontale, meanwhile, face a tricky opener against Malaysia's Johor Darul Ta'zim in Group I, which also features twice winners Ulsan Hyundai from South Korea and Thailand's BG Pathum United.

The group stages of the competition, the last under the current format, run until Dec. 13 with the knockout rounds kicking off on Feb, 12, with the final to be played home-and-away on May 11 and 18.