A third A-League pre-season game was marred by crowd trouble, with 11 fans ejected during Western Sydney Wanderers's 2-1 loss to NSW Premier League club Sydney United.
Police were forced to make an arrest after a flare was thrown from among United supporters at one end of the ground.
The incident comes in the wake of a weekend brawl during the match between Newcastle Jets and Wellington Phoenix that resulted in 13 weeks worth of bans for four players.
On the field, Wanderers players tasted their first defeat since the club's inception.
United went a goal up at halftime thanks to a strike from Mitchell Stamatellis but striker Mark Bridge brought Wanderers level with a scrambled goal on the hour.
United sealed its win with a twice-taken penalty by Ben Vidaic 10 minutes from time.
Wanderers coach Tony Popovic was not overly concerned with the result.
“Certainly, it wasn’t what we were after on the scoreboard but this is all part of the process for us,” he said.
“We will learn from this and take a number of positives out of the match and we now head north for a pre-season camp which will be good.”
Goalkeeper Mat Ryan, defender Pedj Bojic and midfielder Oliver Bozanic look to have played their last games for Central Coast Mariners as the A-League champion faces a raft of departures.