Tony Popovic's team have reached the season decider for the second campaign in succession after edging last season's champions in Parramatta
Goals in either half from Youssouf Hersi and Iacopo La Rocca proved the difference as the Wanderers gained a measure of revenge for defeat against the same opponent in last year's season decider.
The match was billed as a tactical battle between two astute coaches and there were intriguing selections on either side, with the Wanderers leaving top scorer Tomi Juric and ball-playing midfielder Aaron Mooy on the bench.
The visitors omitted the physical presence of Matt Simon, despite the striker not making the midweek trip to Japan, with the pacy duo of Mitchell Duke and Bernie Ibini included.
Matches between the two teams had been tight over the past two seasons since the Wanderers' inception, with an average of just 1.71 goals per game over that time.
Indeed, while the match started with good tempo and attacking intent, a tight contest seemed assured and so it proved.
Wanderers fullback Adam D'Apuzzo was forced into an awkward clearance near his goal line as the Mariners pushed for an early opener.
At the other end, Nikolai Topor-Stanley crashed a header against the crossbar from just five yards, Shinji Ono's corner too much for Mariners' goalkeeper Liam Reddy to deal with.
It was the Wanderers who scored the crucial opening goal as Hersi nudged the ball home from close range on 31 minutes, after Brendan Santalab had driven a pass across the face of goal with Mark Bridge's fierce effort only half cleared.
The goal saw the intensity lift even further and almost immediately Duke fired a shot into the side-netting after a trademark Mariners counter-attack.
Crowd favourite Ono, in his final A-League game at the venue, then forced Reddy into a sharp catch from a curling free-kick.
With their season on the line it was the Mariners that commenced the second period with the greater intensity, and Duke and Ibini always looked likely to cause havoc without fully finding their combination.
Duke stung the palms of goalkeeper Ante Covic just past the hour mark, while Hersi had a chance to virtually end the contest but directed his header from Labinot Haliti's cross just inches wide of Reddy's post.
Substitute Kim Seung-Yong floated a free-kick onto the roof of the net as the home fans momentarily had collective hearts in mouths.
However, with nine minutes remaining the Wanderers took full advantage of the Mariners pushing forward in search of an equaliser, and Hersi released La Rocca who finished with ease past the exposed Reddy.
Western Sydney Wanderers 2 (Youssouf Hersi 31', Iacopo La Rocca 81')
Central Coast Mariners 0
Crowd: 19,216 @ Pirtek Stadium