The Roar had lost their previous five A-League Women finals appearances since beating Canberra 2-1 away in February, 2014.
They could not be denied at a sold-out Spencer Park in Brisbane on Saturday, with attacking midfielder Kijah Stephenson scoring two brilliant second-half goals in the elimination final.
Aimee Medwin added her third goal in as many matches in the 83rd minute to seal the deal.
The Roar play the first leg of their semi-final at home next week against the Phoenix.
"We are absolutely buzzing. The girls were fantastic tonight. From start to finish they were all over Adelaide," Roar coach Alex Smith told AAP.
"To win comfortably and do it here in front of a sold-out crowd at home is what dreams are made of."
Stephenson had the home crowd of 3500 in raptures in the 51st minute when she blasted her shot home for a 1-0 advantage. Her second, six minutes later, was with her left foot in a goal of pure class.
"Kijah is special. I have known her since I joined the program and she is probably one of the most talented players in the country," Smith said.
"She is a player that needs to be backed and given freedom, and when you do she will produce something like that."
The Roar had 14 shots at goal with three on target in the first half, with the visitors having just Erin Healy's header as a scoring chance.
Stephenson made her first shot in the second half count after a great run and through-ball by midfielder Alicia Woods.
Striker Daisy Brown then dinked a delightful pass through to forward Ashlyn Miller, who found Stephenson. Her clinical finish put the Roar on their way to victory.
There was early tension in the match, with Roar captain Momo Hayashi and Adelaide midfielder Sarah Morgan engaging in a verbal altercation and then a push-and-shove.
Teammates rushed in to separate the pair, and the partisan crowd also had their say.
The best early chance fell to the visitors when tall forward Healy's powerful header was saved one-handed by a diving Chloe Lincoln.
Healy went down with a right ankle injury in the 15th minute but bravely battled on.
Stephenson, always dangerous, had a hot shot deflected wide, then Hayashi hit the far post from close range after a corner.
Stephenson had a left-foot rocket brilliantly saved by Ilona Melegh when the Young Matildas goalie stuck out her right foot to save Adelaide.
Melegh then denied a blistering half-volley by Hayashi on the cusp of the break.
After halftime the Roar totally dominated, with Stephenson's two goals and Medwin's clincher knocking the stuffing out of Adelaide.
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