Set to join Japanese side Kyoto Sanga in the coming days, Tulio received a pass from Josh Nisbet in the 25th minute of Saturday's contest and rifled a long-range effort into the net, giving his side a lead they would not relinquish.
It provided a fitting end for the Brazilian's tenure in Gosford, one that included an ALM championship and 24 goals in 48 appearances.
Unbeaten in their last 10 games across all competitions, the Mariners provisionally vaulted into the league's top four with the win, a point behind third-placed Wanderers, who have lost three of their last five.
With Lawrence Thomas away on Asian Cup duty, the hosts were forced into another goalkeeping reshuffle when Jack Gibson went down during the warm-up, forcing Daniel Margush into action and outfielder Anthony Pantazopoulos to don the gloves as back-up.
More injury headaches for coach Marko Rudan came just before halftime when midfield import Jorrit Hendrix limped off after some physical treatment across the opening period.
The Wanderers had more shots across the opening half but struggled to trouble Danny Vukovic in the Mariners goal, with several efforts sent straight at the keeper.
Nicolas Milanovic was the home side's main creative spark and went close on two early occasions as his side pressed forward with renewed energy during the second half.
Angel Torres, Tulio, and Jing Reece all flashed danger as the Mariners looked to respond on the counter - although the visitors were also dealt an injury blow when Alou Kuol was forced off with a hamstring complaint.
Substitute Oscar Priestman had an 89th-minute chance to level things but his effort was sent straight at Vukovic.
8°C