Assat's win over KalPa on Thursday had seen them take pole position in the multi-club race for fourth, but Lukko put in a statement performance in their first 20 minutes that all but earned them the place back.
Two goals in less than 20 seconds of play set the Rauma side on course - Alex Beaucage opened the deadlock on the first powerplay, before Antoine Morand proved Lukko could be just as deadly without a man advantage.
But just for good measure, a second powerplay with just over seven minutes to play in the first period was also used to full effect, as Antti Saarela put the home side 3-0 ahead.
KooKoo threatened a fightback early in the second when Robert Rooba got them on the scoresheet, only for Alex Peters to respond within two minutes to restore the three-goal cushion.
There would be no Lukko reply when Samuel Valkeejarvi scored early in the third period, but nor were there further strikes from the visitors, meaning the hosts had themselves a 4-2 win and just their second three-point success in their last seven, as they finally reached 100 points.
It's two defeats on the spin now for KooKoo, but their deficit to leaders Tappara was only extended by one more point - to four - as the Battle Axe were beaten 4-3 after overtime by Ilves in a thrilling Tampere derby.
Joachim Blichfeld's goal looked to have handed Tappara control of the game late in the first period, after teammate Kristian Tanus had cancelled out an early opener from Luke Henman, only for an illegal check to the head from Aapeli Rasanen early in the second let the Lynx back in.
Carl Klingberg netted on the resulting powerplay nine minutes into the second period, and then a delay of game provided Ilves with another man advantage before the midpoint, which they profited from through Henman's second of the match.
Whatever Henman could go, Blichfeld could do too, as he completed his brace with only 02:34 left in regulation, yet it proved to be fruitless for Tappara, who conceded three minutes into overtime, as Peter Quenneville won it for the yellow and green half of Tampere.
Ilves remain seventh but are just five points off the top four with a game in hand, as they put an end to a two-game losing run. For Tappara, it's a first defeat in four.
JYP suffered a costly first defeat in three which leaves them a point shy of Lukko in fifth place, as Verneri Ahonen was the only player to score in the shootout, as Jukurit caused an upset away from home, 4-3. The Mikkeli side climb to 14th, five points shy of the postseason places.
Hameenlinna are the side Jukurit have their sights set on after they went above TPS Turku into 12th by beating Karpat 3-2 for a fourth win in five, as the Oulu side return to losing ways and now need a minimum seven points from their last four games to reach the playoffs.
Putting breathing space between themselves and the chasing pack were 11th-placed IFK Helsinki, who ended Pelicans' four-game winning streak with a 4-1 win in Lahti that gives the capital side a five-point lead over TPS, as Sabastian Repo netted twice for the victors.