Tappara's nearest challengers a matter of days ago, defeats to lowly Karpat and Vaasan Sport saw Lukko drop away, and now Assat were on the hunt for a second win in 24 hours over the Rauma side following their 2-1 success in overtime yesterday.
Their attempts to kick Lukko while they were down began well when Sakari Kostilainen broke the deadlock in the fifth minute, and though Alex Peters equalised soon after, goals late in the opening period from Johan Olofsson and Feetu Knihti set Assat on course for victory.
Valtteri Viljanen's goal early in the second period only strengthened the Pori side's dominance, before Oskar Nilsson made it 5-1 seven minutes into period three.
Two goals in a matter of seconds from Antti Saarela and Aarne Intonen briefly threatened a comeback, but they were no more than consolations in the end. The 5-3 final score marked a third win in four for the Aces, who remain in eighth place but are only three points behind Lukko in fourth.
Assat are, in fact, only four points off third place, as JYP were beaten for the first time in four matches in unorthodox fashion. After no goals in 60 minutes, neither they nor KalPa could break through in overtime either, as Stefanos Lekkas made 28 saves for the hosts, and Oskari Salminen made 21 for JYP.
Cade Borchardt finally put the puck in the net with the only goal of the shootout, to earn the Kuopio side a 1-0 victory, their sixth in a row, to move just one point shy of Lukko.
As the teams below them falted, the top two pulled further clear but only after a few scares - leaders Tappara threw away a 3-0 lead at home to TPS Turku, before Kristian Tanus got them out of trouble to seal the 4-3 win - their second in a row.
SaiPa stay four points back after they returned to winning ways against Karpat. The Oulu side twice pegged them back, but four goals in the third period allowed the home side to pull away in the end and win 7-4, ending 15th-placed Karpat's two-game winning streak.
There are two more sides level on 72 points with KalPa, ready to pounce on any more slip-ups from the top four - KooKoo, who returned to form with a 5-1 cruise past Kiekko-Espoo thanks to a Veeti Miettinen hattrick, and Ilves, who came from 2-0 down to beat Jukurit 3-2 after OT.
While only four points separate third and eighth, there are 12 points between eighth and ninth-placed IFK Helsinki, despite their 4-0 win at Hameenlinna in which Hugo Alnefelt made 25 stops in the shutout.
12 points is also how far Vaasan Sport are adrift at the bottom, after they lost a third game running, beaten 3-2 by Pelicans, who are only outside the Playoff places on points difference, as they recorded a third win in a row.