Brisbane Roar's chances of progressing to the next phase of the Asian Champions League took a major blow on Tuesday.
The reigning A-League champions, who again qualified for the domestic Grand Final recently, were beaten 2-1 at home by South Korean Club Ulsan Hyundai, leaving them six points behind on the Group F table.
Colombian ace Juan Velez opened the scoring for Ulsan in the 11th minute when he dispossessed Mitch Nichols before guiding the ball past Michael Theoklitos before Shane Stefanutto leveled for the Roar in the 25th minute.
The defender ran onto a neat ball from Massimo Murdocca to slot home past Ulsan keeper Kim Seung-gyu to give Brisbane hope in front of their home supporters.
But with just over 15 minutes remaining, Ulsan skipper Kwak Tae-hwi converted from the penalty spot after Mohamed Adnan had brought down Kang Min-soo in the area.
Matchday 5 will see Brisbane head to group leaders Tokyo on May 2 with a win absolutely vital as Beijing host Ulsan who also need victory to give them hope of moving into the knockout phase.