Defeat at home would not only end Malmo's season but see them bow out on the end of a whitewash, but it seemed their visitors were giving them every chance of a lifeline with a spate of powerplays in the opening period, the last of which the hosts took advantage of.
Neat build-up play down the left side resulted in Robin Salo taking aim from quite far out, his shot flew through a crowd and past Strauss Mann in the Skelleftea goal, who saw it late. The goal 19 minutes in was one of only three Malmo shots on goal in the first period, while Skelleftea had 12.
The first seeds kept their discipline in the second period and still dominated the shot count, 14-6, and were finally rewarded for their attacking endeavours in the 34th minute of the game, when Max Krogdahl's powerful centre flicked Oskar Vuollet and went in.
After 60 minutes, the shots on goal read 35-12 in the away side's favour as Skelleftea's domination continued in the third period, but this time the Redhawks held out to take the match to overtime.
It still looked to be a case of 'when' not 'if' Skelleftea grabbed the winner, until the seventh minute of OT, when Zeb Forsfjall was called for tripping.
That was the chance Malmo needed to win the game 2-1 against the run of play, and just over a minute later, Linus Oberg found Topi Niemela to bury an unlikely overtime winner and cut Skelleftea's series lead to 3-1 ahead of game five on 31st March.
Lulea are one win away from reaching the semi-finals again after a third overtime victory in four matches against Frolunda - this one lasting almost two hours before the winning goal finally made it 4-3 to the home side.
Frolunda won game two 7-0 in between the first two overtime defeats, and must have been thinking another big win was on the cards after Jacob Peterson put them ahead in the seventh minute, before a swift counter-attack saw Jere Innala sail away to double the lead late in the first period.
The home side were back in the match two minutes into the second through Eetu Koivistoinen, only for an off-balance Nicklas Lasu to dig out a finish and restore the two-goal lead. However, Lulea wouldn't go away, and Anton Levtchi made it 3-2 with just over five minutes to play in the period.
And the Frolunda lead was finally stamped out in the seventh minute of period three, when Linus Omark set up Koivistoinen for his second of the game.
Recent results made Lulea the favourites for overtime, and they thought they had won it with just over two minutes played when Oskari Laaksonen tapped home, only for a successful coach's challenge to see the goal ruled out for interference on the goaltender in the build-up.
That was the only time the puck found either net in the first 20-minute overtime period, meaning a second would be required. Either side of the 90-minute mark in the match, Ivar Stenberg was called for tripping and Oskar Engsund for interference, yet neither side could profit on their powerplays.
On Saturday, a 125-minute match between Assat and SaiPa broke the record for the longest match in Finland's Liiga, and just 24 hours later, these teams came very close to playing for even longer, before Lulea finally scored the winner with 117:29 played.
Omark was again the provider, this time for Mathias Brome to score his second playoff goal of the postseason so far, rounding off the second-longest match in SHL history.
The Gothenburg side must pick themselves up and go again in game five back at home on the 31st March to prevent Lulea from reaching the last four.