It's a record-extending fifth CHL title for the club from Gothenburg, but their first for six years. For one-time champions Lulea, it's the second time they have finished as runners-up in the last four seasons.
Since beating fellow Swedish side Brynas in the semi-final, Frolunda's form had taken a nose dive, as they relinquished first place in the SHL after just two wins in their previous 11 matches, which included a 7-3 beating at the hands of Lulea.
Lulea also came into this on the back of a loss, albeit after penalties against the new SHL leaders Skelleftea, and it was just their third defeat in their previous nine.
The reigning SHL champions also came into this with history on their side, having beaten Frolunda 4-2 in the 2015 Final, the only previous all-Swedish affair.
That said, the visitors only managed one shot on goal to Frolunda's five in the opening 12 minutes, though their one chance from Benjamin Tardif rivalled anything from the hosts for the best early effort, as Linus Weissbach's strike at the other end tested the reactions of Matteus Ward.
A physical first period threatened to boil over as both sides increased their shot count but had to be separated by officials more than once in the final minute, but the match was still goalless when 20 minutes were up.
The Gothenburg side had the first real chance of the middle period, as Ivar Stenberg was denied by Ward when hooking the puck goalwards after a powerful Nicklas Lasu strike got caught in traffic.
But at the other end soon after, a flowing Lulea moved resulted in a golden chance for Anton Levtchi on the right side, but his one-timer was kept out by a combination of the post and a spread-eagled Tobias Normann.
Approaching the midpoint in the match, the momentum looked to have swung in Lulea's favour when Innala was called for tripping Markus Nurmi, and the away side had the first powerplay of the Final.
However, Frolunda decided that attack was the best form of defence - they began the powerplay with Lasu teeing up Max Friberg for a great chance right in front was blocked by Ward, and ended it by scoring the shorthanded goal they had been threatening with one second left.
Lasu stole the puck in the defensive zone and skated clear through the centre, before slotting it past Ward in real style.
Even with the penalty over, Frolunda continued in the same vein for the rest of the period, as Normann kept out a flurry of late Lulea chances and the home side looked to counter-attack swiftly, but it remained a one-goal game with two periods in the books.
However, with less than two minutes played in the third period, the match was level again. Ward had been called upon once more to pull off a splendid stop against Arttu Ruotsalainen, and that looked all the more crucial moments later when Eetu Koivistoinen tipped Mathias Brome's shot past Normann.
A potential high stick from Brome meant the goal was checked, but the video review saw no reason to rule it out, and the goal stood.
But once again, the first powerplay of the period would prove decisive - Lulea's Oskari Laaksonen was called for cross-checking, and after a long period of patient build-up, Frolunda found a way through.
With a goal similar to the one they had just conceded, Henrik Tommernes took aim from range, and a big deflection from Jacob Peterson sent the puck bouncing past Ward and into the net.
Max Lindholm failed to add a finishing touch after a mazy run from Theodor Niederbach as Robert Ohlsson's side passed up a chance to wrap things up, then inside the final five minutes, the Norrbotten side were given a real helping hand when Christian Folin was penalised for holding.
Lulea pulled the goaltender during the powerplay, but even with two extra attackers on the ice, they failed to find a way past Normann and his disciplined defence.
That looked to be that for the visitors, until 15 seconds of regulation time remaining, when a hopeful Brian O'Neill pass across the front sailed through the crowd and out to Otto Leskinen on the left side, who needed no second invitation to fire the puck into the top corner.
That meant overtime was required, and despite the late blow it was the hosts who were pushing harder to win it, as they had the only two goalbound strikes in the first four minutes, before Brome was sent to the box for holding the stick with 04:21 played.
Playing a man down, Lulea could not come close to clearing their own zone, and the pressure told 35 seconds into the powerplay, when Tommernes had time to slide the puck across to Innala on the right, and his strike was just too strong for Ward in the Lulea goal.
The home bench and the Scandinavium went wild, as Frolunda took the 2025/26 CHL title with a 3-2 overtime success, as they remain on course to do an SHL-CHL double and wrestle another title away from Lulea.