Brisbane's star signing Marco Rojas scored a double in a 3-2 upset win over his former A-League Men club Melbourne Victory as the Roar's supporter group, The Den, staged a walkout at Suncorp Stadium.
The Den exited the arena in the 25th minute - soon after Rojas had scored the opener - in protest after fans had altercations with the police on the way in.
Veteran Rojas, in his first starting game for the Roar, scored his maiden goal for the club with a composed, looping header after a shot by 18-year-old Thomas Waddingham was deflected by Victory goalkeeper Paul Izzo.
Victory's Zinedine Machach equalised with a cracker, producing a scything run down the left and letting rip just inside the box with a shot that gave Roar goalie Macklin Freke no chance.
Rojas's second goal was pure class as he unfurled a diving header at the far post after an inch-perfect pass by Keegan Jelacic in the 56th minute.
He was substituted not long afterwards but an alert Waddingham stepped up to tap home after a shot from Henry Hore was deflected by Izzo.
Roar acting head coach Ruben Zadkovich said it was "scary" how much more Rojas had to offer.
"I thought he was good in some moments and I thought he has still got a lot to improve," Zadkovich said.
"He has been out of the game a long while. But in the last few weeks he has really started to turn the screws at training."
Journeyman Roly Bonevacia gave the Victory a sniff when he came off the bench and scored in the 86th minute with a precision strike on his club debut.
The Roar remain in the finals hunt on 25 points. They are three points behind sixth-placed Western Sydney but have played an extra game.
Victory are fourth and never got going against the Roar in hot and humid conditions.
"It was difficult conditions," said Victory coach Tony Popovic, "but today was a poor defensive effort from us.
"We scored two goals but I can't remember us conceding three soft goals like that this year."
Rojas was the star of the afternoon, with his composure and silky touches on the ball pivotal.
There was high drama in the sultry condition when a group of 30 to 40 supporters who sit in The Den seats at the northern end of the stadium left.
Video of a push and shove by fans with police was earlier posted on social media site X. A police officer can be heard to say "that sort of behaviour will not be tolerated".
Zadkovich was unaware of The Den's exit.
"It is the first I have heard of it but our fans are fantastic and their support is exactly what we need here at home," he said.