After Ilves enjoyed one narrow and one comprehensive victory to start the Tampere derby series, Tappara hit back with one narrow and one clear victory of their own to level the contest.
Someone had to take the overall lead in game five, but there was no indication as to who would take it over the first 40 minutes, which remained goalless, as Ilves didn't make use of three powerplays to Tappara's one, and even briefly had a 5-on-3 situation, though Tappara had 16 shots on goal to Ilves' 14.
Finally, the deadlock was broken nearly nine minutes into period three, when the Battle Axe came bearing down on Ilves' goal before Jesper Mattila's effort was saved, but picking up the rebound a firing into the net was Henrik Haapala.
Two further powerplay chances came and went for Ilves, but as it turned out, they were most effective when they were a man down - after John Nyberg was called for cross-checking, it was Simon Johansson's turn to score a rebound goal, equalising when shorthanded with 97 seconds to play.
That sent the match to overtime, in which the designated visitors failed to use the momentum from the late leveller, and instead it was Tappara who won it 2-1 six minutes in, when Kristian Tanus deflected in Aleksi Matinmikko's shot from the blue line.
The regular season champions are now one win away from the finals, and their first chance to get it will be on Monday 27th in front of Ilves' fans.
Also one victory away from contesting the Kanada-malja are KooKoo, who went 3-2 up in their series by thrashing SaiPa 4-0 at home, just 24 hours after they were on the end of a 3-0 shutout loss in Lappeenranta.
The wait for the opening goal was much shorter in Kouvola, where Kalle Loponen's one-timer from the blue line took a thin deflection off Miska Siikonen's stick en route into the SaiPa net.
Tempers then began to boil over, as twice in the opening 20 minutes a player from each side was penalised for fighting, and it was still a one-goal game 40 minutes in, as neither team could profit from a powerplay apiece in period two.
But KooKoo did just that five minutes into the third period, after Miikka Salomaki was called for slashing, the home side won the face-off which was worked back to Jiri Parssinen, whose shot flew into the top corner.
And the second seeds all but put the game to bed six minutes from time when Ossi-Petteri Jaakola reacted quickest to the rebound after Ari Grondahl's effort was saved and buried his follow-up.
KooKoo then did wrap things up with just over a minute to play, when Robert Rooba struck into an empty net to complete the win, giving them the chance to win the series in game six, which is also set for Monday 27th, in Lappeenranta.
It was a memorable night for Eetu Randelin, who made 27 saves to complete a second shutout of the 2026 playoffs.