Ten days had passed since KooKoo completed their series win over Pelicans, while SaiPa needed two more games to see off Assat, completing the 4-3 series success four days earlier.
It was therefore a question of whether KooKoo's freshness or SaiPa's match sharpness would prevail in game one, and 15 minutes in, everything looked to be pointing in the visitors' favour, as they opened up a 2-0 lead.
First, Antti Kalapudas found Otto Kivenmaki, who opened the scoring after 12 minutes, and then Eero Klintrup drew the defence as he skated behind the net before pulling the puck back for Juuso Heikkila to squeeze his shot through Eetu Randelin.
Having taken a period to get up to speed, KooKoo hit back eight minutes into period two, when Miska Siiknonen - who reaced the finals last season with SaiPa - controlled the puck patiently on the left wing before pulling it back for the unguarded Veeti Miettinen in the centre, who swept it home.
But it was in the third period when the fresh legs of the Kouvola side made the difference - KooKoo equalised seven minutes in via the same combination, as Siikonen wrapped around the net before squaring for Miettinen to finish from close range.
And with just over 10 minutes to go, the home side completed the turnaround when Miettinen was knocked off the puck behind the net, but Siikonen was on hand to pick it up, and this time he didn't need a teammate to finish off his wraparound, beating Kari Piiroinen with a nice shot.
In the final five minutes, the number-two seeds secured the 4-2 victory when Kim Nousiainen teed up Siikonen to complete a brace and reach four points in the match, handing KooKoo a 1-0 series lead ahead of game two in Lappeenranta in under 24 hours time.