Kif Örebro was one of the few teams that managed to score against Häcken during last year's season.
In Sunday's meeting between the teams, however, they went scoreless, and it became a one-sided story.
After just over half an hour at a sun-drenched Behrn Arena, Häcken's Lotta Ökvist, formerly Manchester United, stayed ahead and steered Stina Blackstenius' shot attempt.
The guests, who had already slipped behind Rosengård in the table, continued to lead the game.
And in match minute 72 also came the extension - much thanks to Örebro's goalkeeper Cecilia Rán Runarsdottir.
A simple side pass to his own player ended up instead with Stina Blackstenius who easily rolled in Häcken's second goal.
This was not Örebro's day, and three minutes after the setback goal, the Canadian Jenna Hellstrom got a red card after a backhand against Anna Csiki in Häcken.
In extra time, the guests also came 3-0, through Diljá Zomers.