Striker Adam Kwasnik scored the only goal as Central Coast qualified for their third grand final in six A-League seasons on Saturday.
After missing a host of great chances, the Mariners finally found the back of the net in the 75th minute when Kwasnik scored his 10th goal of the season against Gold Coast United in the preliminary final.
Midfielder Michael McGlinchey had a shot blocked by a Gold Coast defender and Kwasnik was in the right spot to capitalise and send the Mariners into a grand final against Brisbane next Sunday.
Despite scoring, the Mariners still had plenty of anxious moments in the final 15 minutes. Teenage goalkeeper Mathew Ryan ensured the home team stayed in front with a brilliant double save from Joel Porter and Bruce Djite in the 78th minute.
The Mariners went into the match as slight favourites and had a great opportunity to open the scoring after only three minutes, but striker Daniel McBreen appeared to stumble as he was about to shoot from close range.
Ryan denied Djite in the 13th minute before the Mariners started to dominate.
Defender Joshua Rose and midfielder Oliver Bozanic both had long range attempts saved and in the 44th minute Patricio Perez had a curling shot just miss the target.
Young defender Trent Sainsbury, who had a tough time in the first half, should have at least hit the target in first half injury time, but miss-hit a volley from a Bozanic cross, much to the frustration of Mariners coach Graham Arnold.
Chances were few and far between in the second half.
The Mariners came close to opening the scoring in the 69th minute when Patrick Zwaanswijk headed a corner on to the crossbar and a minute later Bozanic sent a glancing header over the bar.
Despite failing to put the Queenslanders away earlier the Mariners deserved the win and now get a chance to win a grand final for the first time.