Adelaide United coach Michael Valkanis watched from the stands as his team defeated 10-man Melbourne Victory 1-0 on Friday.
Interim coach Valkanis was dismissed by referee Jarred Gillett in the 41st minute at Hindmarsh Stadium for expressing his anger after having five players booked within in the first half.
The 38-year-old's ejection inspired the hosts though, as Jeronimo Neumann returned from suspension to head in the eventual winner just seconds later.
Jeronimo's strike was enough for Adelaide, who held on in a second half that saw Victory full-back Adama Traore harshly sent off.
A 12,025 strong crowd – Adelaide's best attendance at Hindmarsh since the 4-2 victory over Victory in December – was in full voice as the home team got one over their traditional rivals.
The result saw the fourth-placed Reds snap a three-match losing streak and move level on points with Western Sydney Wanderers, who play Newcastle on Saturday.
Victory are second, one place and one point ahead of the Wanderers.