Central Coast will face Western Sydney in next weekend's Australian A-League final after beating Melbourne Victory 1-0 at home on Sunday.
A 42nd-minute long-range strike from Daniel McBreen, this season's golden boot winner, proved the winner to put the Mariners into their fourth title decider in eight seasons.
It was a coaching triumph for Graham Arnold, who had to rotate his squad for a mid-week trip for the Mariners to China to play Guizhou Renhe in an AFC Champions League match.
But former Sheffield United midfielder Nick Montgomery will miss next week's final for the Mariners after he was sent off in stoppage time for his second yellow card after a foul on Mark Milligan.
Victory's loss ended an unblemished finals record for their coach Ange Postecoglou, who led Brisbane Roar to back-to-back championships, and had not tasted defeat in seven previous A-League finals matches.
Japanese star Shinji Ono produced an exquisite goal on Friday to propel Western Sydney Wanderers into the final in their debut season.
Ono's dipping chip into the top right corner clinched the Wanderers a 2-0 win to dump defending champions Brisbane Roar out of the championship title race.
Tony Popovic's Wanderers are now one win away from being crowned champions, having already created Australian sporting history by securing the first-past-the-post Premiers' Plate to become the first expansion club to win silverware in their inaugural year.
Croatian striker Dino Kresinger set the ball rolling with an audacious back-heeled goal to give the Wanderers the lead in the 16th minute.
But Ono, 33, who played for Japan 56 times and appeared in three FIFA World Cups, crowned Western Sydney's triumph with his magnificent goal in the 71st minute.
The Wanderers head into the final on the back of a 13-game unbeaten run denying the Roar a shot at their third straight championship.