Adelaide United's loss to Shandong Luneng on Tuesday night should serve as a reminder for Melbourne Victory and Sydney FC of the challenges of playing in the AFC Champions League (ACL).
Hyundai A-League clubs should not interpret Western Sydney Wanderers' ACL triumph in 2014 as a sign that the level of Australian football is automatically up to scratch in Asia's premier club competition.
Defensive errors and a lack of polish in the final third can sometimes be brushed under the carpet in the A-League, but against the best sides in Asia, those mistakes are clear to see.
Adelaide's 2-1 play-off defeat at Coopers Stadium came down to those two weaknesses of the Australian domestic game.
Poor errors - particularly for Shandong's first goal - allowed the Chinese Super League club to surge to a 2-0 lead at the break.
And although a red card to Wang Yongpo with 20 minutes left gave the hosts the upper hand, Adelaide couldn't take advantage of enough chances in the closing stages.
This was far from a poor performance from Guillermo Amor's men, but it was a stark example of how little room for error there is in the ACL.
The pre-match comments of Adelaide captain Eugene Galekovic were prophetic: "The biggest difference [in the ACL] is you play A-League opposition and you might get away with a few mistakes.
"Against a team like Shandong, you make a couple of mistakes and you probably get punished if you give away the ball in certain areas."
Galekovic was partly to blame for exactly that in the 17th minute as launched a counter-attack by riskily throwing the ball straight down the middle to Marcelo Carrusca.
In his defensive half and under pressure from Shandong defensive midfielder Jucilei, Carrusca lost possession easily, allowing Walter Montillo to surge past both of Adelaide's central defenders and shoot at Galekovic.
While the Reds goalkeeper made a good save, the rebound was headed into the net by Yang Xu, who hadn't been tracked by Dylan McGowan.
Shandong's entire attack barely took five seconds but suddenly Amor's team were behind.
The visitors' second goal had more structure to it but again Adelaide were at least partly culpable.
The home side failed to clear a high ball in defensive midfield and were on the back foot from that moment, with Montillo given too much time on the ball to eventually release an unmarked Yongpo on the left.
Diego Tardelli was then allowed to drift between McGowan and Jordan Elsey to glance a header past Galekovic from Yongpo's cross.
Victory coach Kevin Muscat and Sydney boss Graham Arnold need to drill into their teams the importance of constant concentration in defence if they are to have better results in the ACL.
At the other end, Adelaide created enough opportunities to win the match but whereas Shandong's attackers had the polish to capitalise - at least in the first half - the Reds' finishing let them down time and again.
Craig Goodwin should have scored after the interval when he had a free header at the back post from a brilliant Carrusca cross, while many other Adelaide players shot straight at Shandong goalkeeper Wang Dalei in good positions.
Carrusca, who was very impressive with his lead-up play, showing off some fine touches and flicks but then smashed his penalty onto the bar late in the match.
It would have been enough to force extra time, as Sergio Cirio would score in the 89th minute.
There is a reason why the Wanderers became Asian champions and Adelaide reached the final in 2008 with tight, organised defences and goals generally coming on the counter-attack and from set-pieces.
Such tactics reduce the opposition's space and time when they have the ball, while attacking on the break and from dead-ball situations generally suits the physique of Australian players.
It remains to be seen whether an A-League club can succeed in the ACL with a more proactive style but regardless of tactics, Victory and Sydney can learn a lot from Adelaide's defeat.