Victory had enjoyed a charmed start to its Asian Champions League campaign, having stunned J.League giant Kashima Antlers in the play-off, then following that win up with a 1-0 win over Thai club Chiangrai United.
That momentum was brought to a halt in Seoul, where the Korean powerhouse took an early lead through former Arsenal star Park Chu-Young, then held on in a free-flowing contest that produced multiple shots at goal for both teams.
Perth Glory - making its tournament debut under former AC-winning manager Tony Popovic - faced a similarly tough encounter, away at FC Tokyo. While the home side created more than double the chances of Glory, the A-League club held on until just after the 80th-minute, when Brazilian Leandro curled home a stunning winner from outside the box.
Defending A-League premier, Sydney FC, is up against a familiar foe when it travels to Japan on Wednesday for a mouthwatering clash against J.League champion Yokohama F. Marinos, managed by ex-Melbourne Victory, Brisbane Roar and Australia coach Ange Psotecoglou.
It will be the Sky Blues' opening match but they will be without influential midfielder Milos Ninkovic, who wasn't included in their Champions League squad.
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