The Mariners, in just their second year back in the competition after a 14-year hiatus, pulled off a stunning underdog story, winning 5-4 on penalties after scores were locked at 1-1 following extra-time.
Injured Matildas captain Sam Kerr was among the 6,568 on hand at AAMI Park for the enthralling contest.
Seven days after scoring a controversial semi-final winner against Melbourne City, Gomez pounced on a calamitous moment at the back from Victory's Claudia Bunge in the 46th minute to score.
Bunge headed home the equaliser from a corner in the 80th minute, forcing the game to extra-time.
Victory were in disbelief when Mariners defender Taylor Ray wasn't penalised for a clear handball in the box in the 93rd minute, while Sarah Langman made a brilliant save to deny Emily Gielnik a minute later.
The Mariners withstood wave after wave of attacks from Victory - who had 30 shots to Central Coast's 15 - to take the ALW decider to spot-kicks for the first time.
After Victory's Alana Jancevski hit the crossbar with the opening penalty, Central Coast nailed every spot-kick, including Gomez's sneaking in after she slipped while taking it.
Bianca Galic converted the winner to send the Mariners into ecstasy.
The triumph completes Central Coast's dramatic run from fourth place, beating Canberra United, Melbourne City and Victory along the way.
"We know there's a lot of critics that didn't have us achieving much or making finals this year and we won out," captain Taren King said on the podium.
"Today was our last push and we made it happen."
Second-year coach Emily Husband earned her first trophy, denying Victory counterpart Jeff Hopkins a record fifth championship.
Husband is just the fourth female coach to win the championship after Jitka Klimkova (2012), Liesbeth Migchelsen (2014) and Jess Fishlock (2016-17, player/coach) and the first in a grand final since 2017.
The result was devastating for Victory, who also fell agonisingly short in the premiership, won by Melbourne City.
Gomez, 22, fresh off a Matildas call-up, was outstanding throughout, consistently driving forward and winning fouls while doing the dirty work in defence.
King, Jessika Nash and Annabel Martin brilliantly kept Victory spearhead Gielnik quiet.
Gun midfielder Alana Murphy was arguably Victory's best.
Central Coast took the lead when Galic pinched the ball from Sara D'Appolonia and found Annalise Rasmussen.
The striker's shot deflected off Kayla Morrison and Bunge missed her attempted clearance, with Gomez nipping in and brilliantly chipping Courtney Newbon.
Victory's equaliser arrived when Murphy whipped in a corner met by Bunge, and Martin couldn't stop the ball crossing the line.
Morrison pulled off an extraordinary game-saving challenge on Rasmussen in injury time to ensure the match went to extra-time.
Victory peppered the Mariners' goal time and again but couldn't break through.
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