Besart Berisha opened the scoring before being sent off as A-League leaders Brisbane Roar drew 1-1 at Sydney on Friday.
Berisha nodded the Roar into a 23rd-minute lead, only for Sebastian Ryall to respond with a header of his own 12 minutes later.
Both players were then involved in a flashpoint prior to the interval, which led to Berisha seeing red.
The Albanian forward lunged into a tackle on Ryall, who was booked after retaliating by pushing his opponent over.
Brisbane made light work of their numerical disadvantage for the remainder of the game and might have claimed all three points.
They now hold an 11-point advantage at the summit, while Sydney are fourth following only their second draw of the campaign.
Thomas Broich provided the cross for Berisha's opener, which saw the 28-year-old drift away from Nikola Petkovic and loop a header over Vedran Janjetovic.
Sydney responded well and pulled level when Ryall converted an inswinging corner from Petkovic.
Liam Miller had a late chance to win the game for Brisbane, but cleared the crossbar after making his way into a promising position inside the penalty area.comments