But this week, it was the AFC Champions League stage where they announced their arrival on after both opened their continental accounts in Asia.
Elsewhere, a couple of Southeast Asian hopefuls looking to emulate their creditable performances from last season got their campaigns back on track after suffering defeat in their opening games.
Here, we take a look at five things we learned from match day 2 of the 2023-24 AFC Champions League.
Big guns off the mark
There was plenty of hype heading into this edition of the ACL given it is the first since the influx of stellar names to the Saudi Professional League, although the opening match day did not see any of them feature prominently.
That has now changed as Ronaldo notched his first goal in the tournament on Monday with an important equaliser as Al Nassr came from behind to beat Istiklol 3-1, before Neymar matched the feat the following evening with Al Hilal's second in a 3-0 victory over Nassaji Mazandaran.
Another recognisable name also opened his ACL account in Al Hilal's triumph in the form of Aleksandar Mitrovic, as the competition's newfound star power showed signs of delivering on its promise.
JDT, LCS get back on track
After falling to Kawasaki Frontale in their Group I opener, Malaysia Super League champions Johor Darul Ta'zim -- who did brilliantly to reach the round of 16 last term -- got their campaign back on track with an impressive 4-2 triumph over Thailand's BG Pathum United.
What was described as a "Group of Death" when the draw was first made now looks set to be just that with JDT and 2020 champions Ulsan Hyundai tied on three points, three behind leaders Frontale while BGPU cannot be written off just yet.
Another Southeast Asian hopeful in Lion City Sailors also bounced back from an opening-day defeat, grinding out a 2-1 away triumph over Kitchee in a Group F that also looks set to be keenly contested with Bangkok United and Jeonbuk Hyundai Motors also vying for a top-two finish.
Geopolitics returns to the fore in ACL
Al Ittihad's new stars such as N'Golo Kanté and Fabinho got their first taste of how Asian football can sometimes be affected by regional and continental geopolitics, as the Saudi Professional League outfit's clash with Iran's Sepahan was called off on Monday.
An official statement released by the Asian Football Confederation said the cancellation was due to "unanticipated and unforeseen circumstances", but it was widely reported that Al Ittihad refused to leave their dressing room due to a statue of an assassinated Iranian general being placed at the entrance of the field.
Relations between the two countries have long been strained and this year's tournament is the first since 2016 that will see teams from both nations playing on each other's soil, with neutral venues having been used previously due to security concerns.
Thailand could once again provide the dark horses
Although they do not boast the same heavyweight status as the likes of Japan and South Korea in the East Asia Zone of the tournament, Thai clubs have consistently punched above their weight through the years -- and the 2023-24 edition could be no different.
BGPU's run to the quarterfinals last term was a commendable achievement while Buriram United -- back in the ACL this season for the first time in five editions -- started emphatically with a 4-1 rout of Zhejiang Professional although they did suffer a 1-0 defeat to Ventforet Kofu on Wednesday.
But it is Bangkok United who could emerge as the dark horses in 2023-24, as they backed up their opening 2-1 win over the Sailors with a upset 3-2 victory over perennial contenders Jeonbuk.
Will Frontale find ACL joy at long last?
Despite their status as champions of the J1 League in four of the past six years, Frontale have failed to make it out of the group stage of the ACL in three of their past five appearances -- although it is far from an anomaly given Japanese teams have at times viewed continental success as a secondary priority.
This year, however, they are already in a strong position after just two games having picked up a maximum six points with wins over JDT and Ulsan to sit top of Group I.
Frontale's hand has arguably been forced as their woeful league form -- which sees them sit 9th on the table and effectively out of the title race -- could mean they have to put all their eggs in the ACL basket, but it would still be far from scant consolation if they can go far in the tournament and surpass their previous best of a quarterfinal appearance.