Marconi coach Peter Tsekenis said he was "frustrated" with their 1-0 loss to Manly United on Sunday at Cromer Park.
After notching three wins in seven days, the Stallions missed a golden chance to edge closer to the top five with the loss keeping them four points behind the fifth-placed Manly.
Former Stallion Charles Mendy's goal in first-half stoppage time proved to be the difference despite James Andrew and Mitch Mallia creating several chances for the visitors who had scored five goals in their past two league games.
"It was very frustrating," Tsekenis said.
"Conceding a goal just before half time the way we did.They took one of their chances and we couldn't take any of ours. I can't recall many other chances they had, so I am just frustrated."
This Sunday (5pm) the Stallions play Hakoah Sydney City East FC at Hensley Athletic Field.
Hakoah have won only two games all season and sit in last place.