Lukko had put together a four-match winning run to return to second place in the standings, and looked to cement that place when Alex Peters broke the deadlock late in the first period, before Antti Saarela doubled the lead approaching the midpoint in the match.
But Lukko's winning run came after a loss to SaiPa, and when Niklas Appelgren pulled a goal back five minutes later, they knew the game was very much alive. A powerplay late in the second came as a welcome relief, especially after Mikael Ruohomaa used to to restore the two-goal cushion.
However, there was only one team who turned up for the final 20 minutes - SaiPa brought it back to 3-2 in the opening minute through Brian Kramer, then Eero Klintrup levelled the scores seven minutes later.
Seven minutes from time, the Lapeenranta side completed the turnaround through defender Teemu Kivihalme to take all three points, to move above KooKoo into fourth following successive wins. The 4-3 loss means Lukko failed to move within three points of leaders Tappara.
Sixth-placed Ilves have moved level with KooKoo on 63 points, but failed to go ahead of the Kuovola side as they needed overtime to beat Vaasan Sport, who remain cut adrift at the bottom of the table.
Charles Bertrand gave the visitors and unexpected lead, before Jens Looke and Carl Kingberg turned things around for the Tampere side. However, despite their form, Ilves couldn't hold on, and Johan Sundstrom grabbed an equaliser with 10 minutes left to force overtime.
Ilves finally got over the line with 03:31 on the overtime clock, as Simon Johansson goal won it, 3-2, to seal an 11th Liiga win in a row, breaking a club record that has stood for nearly three decades. The point takes Sport to within eight points of Hameenlinna.
Elsewhere this evening, Assat held off the challenge of Karpat to register a 4-3 home win - their second in three matches - to close the gap on Ilves to one point, while the Oulu side remain four points shy of the Playoff positions.
Moving back into those Playoff places were IFK Helsinki, who romped to a comfortable 5-1 victory at home to KalPa, climbing to 11th in the table following successive wins, and putting an end to the eighth-placed Kuopio side's three match winning run.