A 2-0 victory in game three left Farjestad a game away from a clean sweep, but they were now up against a Rogle side determined to keep their season alive, and the visitors made the better start, but crucially were unable to break the deadlock in a first period in which they led 15-6 on shots on goal.
The visitors almost invited FBK to punish them early in the second period, conceding three penalties in just over six minutes, even briefly going down to 5-on-3, but it wasn't until the 12th minute of the period that the blow was finally landed.
Linus Johansson held off the Rogle defence behind the net, and laid the puck back for Lucas Forsell to fire a one-timer past the goaltender. But any hopes the home side had of pulling clear were dashed just a minute later, as Calle Sjalin set up Paul LaDue to keep the match and the series alive.
LaDue was then called for interference soon after, but that only served to usher in four penalties conceded by the hosts, two either side of the second break.
The fourth of those - high-sticking by Filip Roos - saw Rogle go ahead on the powerplay, when Lubos Horky found Linus Sandin, and his goal eight minutes from time won 2-1 it for the Angelholm side and kept the series alive.
Vaxjo were twice pegged back but finally held on for a 3-2 win away at Brynas that sees them take a 3-1 series advantage.
The Lakers went in front after an interference call against Axel Andersson gave them their first powerplay, which resulted in Leo Sahlin Wallenius finding Dylan McLaughlin to strike for goal with just over 15 minutes played.
But the home side were level in the final minute of the opening period, as Jakob Silfverberg played the puck across from the right and went in off the skate of Johan Larsson, who didn't seem to know very much about it.
Parity only lasted until the fifth minute of the second period, as Sahlin Wallenius was again the provider, this time for Eemeli Suomi to put Vaxjo ahead again with what turned out to be the only goal of the period.
Into the final 20 minutes, Suomi turned from hero to villain, dismissed for cross-checking in the sixth minute, and soon after Brynas made the man advantage count, as Silfverberg turned from provider to scorer to level following Anton Rodin's pass.
Within seconds of getting back to full strength, the visitors found themselves a player up after Brynas were guilty of too many men on the ice. And with 02:45 left on the clock, Brogan Rafferty struck on the powerplay to win it 3-2 for Vaxjo and put them a win away from the semi-finals.
Game five of both quarter-finals will be played on Wednesday 1st April.