Abi Harrison scored a dramatic late winner as Hibs beat Glasgow City to set-up a SWPL Cup final against Celtic.
With the game goalless and heading for penalties, Harrison pounced on a Siobhan Hunter cross to settle it in the league leaders' favour.
Celtic had earlier booked their first SWPL Cup final place since 2010 with a 2-1 win over Spartans.
Colette Cavanagh scored early for Spartans, but Kirsty Howat and Suzanne Mulvey put Celtic into the final.
The two sides will meet in the final at Broadwood Stadium, Cumbernauld, on 21 May.
Something to prove
It was the champions against the league leaders and both sides arrived at Ainslie Park aiming to put down a marker for the season.
City, the Scottish title holders for the past 10 years, are under threat of being dethroned by last year's double cup winners Hibs.
League business may have been put to side for one week, but it promised to be an early indicator of what to expect in the title race.
For the first 45 minutes, the answer was disappointing. The sides cancelled each other out, although Katey Turner and Rachael Small headed wide for Hibs and, at the other end, Leanne Ross sent a free-kick past the post.
Both defences continued to be on top in the second half, but the chances were at least becoming more frequent.
City's Irish signing, Noelle Murray, found the roof of the net with a lob before Hibs' Amy Gallacher had a shot well blocked by Savannah McCarthy.
If a goal was to come in 90 minutes then Scott Booth's side were looking the more likely to find it; Lauren McMurchie and Brogan Hay firing wide and Kodie Hay meeting a header at the back post that Hibs defended well.
Into extra-time it went. City's lively 18-year-old, Brogan Hay, crossed for Megan Foley, who headed wide, but after that, Hibs took the initiative.
Cailin Michie and Harrison both shot wide from the edge of the area before the controversial moment of the game arrived.
Harrison rounded goalkeeper Lee Alexander and hit the deck. But, to the fury of the Hibs bench, she was booked for diving by referee Vikki Robertson.
Their jeers were turned to cheers two minutes later, with penalties just moments away, when Hunter's shot spun into the path of Harrison, who slid in at the back post to win it.
Celtic bounce back
Spartans had started the season unbeaten and, after five minutes, they were ahead when Cavanagh broke free on the counter attack and slotted the ball past Celtic goalkeeper Megan Cunningham.
As the game went on, Celtic rose in dominance, although Cunningham reacted quickly to deny Alana Marshall then Sarah Clelland.
Her opposite number, Rachel Harrison, denied Howat with a brilliant one-handed to tip the ball around the post, but 10 minutes before the break, it was 1-1 when Howat latched on to Darcy McFarlane's through ball and coolly picked her spot.
In a bruising second half, Spartans lost Ronaigh Douglas to injury, before Marshall was carried off with what was later revealed to be ankle ligament damage.
With 15 minutes from time Celtic found a winner.
Mulvey sneaked in behind the defence and knocked the ball beyond Harrison to send Celtic into the final.
Celtic head coach David Haley: "We made very hard work of it. The first half, we made life very difficult for ourselves.
"We had to get used to wind. We made a mistake with that Spartans goal. After that, we controlled the game though.
"We dictated the pace, created chances.
"Bringing on Sarah (Ewens) and Suzanne (Mulvey) to make the contribution they did was massive for us.
"I said to the girls weeks ago that all players are going to be important to the squad and they've shown that today."
Hibs head coach Chris Roberts: "I'm immensely proud of the girls.
"I thought we should have had the game finished in 90 minutes, but of course you go into extra-time, I personally felt we were more on the front foot. I thought the girls deserved the win.
"Rarely are the games in the cup against Glasgow City settled in 90 minutes.
"It's a testament to our squad in standing up to a team who have been serial winners over the last 10 years; it's great to see us get some success now.
"But we've still not won anything, Celtic will be a really tough test."