Vasteras had the chance to move five points behind third-placed Hammarby, but instead they were not only handed a second loss in three matches, but at home to Halmstad, who won away from home for the first time all season and are now five points from guaranteed survival.
Both goalkeepers were forced into action in the first half, with the visitors' Tim Ronning doing brilliantly to deny Axel Taonsa when one-on-one, but his resistance was broken in the final minute of the half, when Jonathan Karlsson opened up his body and guided the ball around the goalkeeper.
Taonsa was again wasteful after the break, while Ronning kept Halmstad alive by denying Mamadou Diagne a spectacular second. Those moments proved crucial, as four minutes from time Gabriel Wallentin lumped the ball forward, and Pascal Gregor used his head to loop it over Elis Jager to level.
And two minutes into added time, HBK went and won it when Hussein Carneil cut in from the left side and sent a 20-yard curler through a crowd and past Jager before he could react. Halmstad have won two of their last four, as many as in their first 21, while Vasteras remain in sixth place.
Elfsborg may be five matches unbeaten, but successive draws have somewhat derailed their European ambitions, as they are four points behind the top three having played a game more. Malmo are five points further behind, and with just one win in four are all but resigned to missing out on Europe again.
The match in Boras was completely lacking in big chances, as the two teams generated just two shots on goal each, with Leo Ostman's effort for Elfsborg the only one to really give the goalkeeper something to think about.
Elfsborg are fifth but can at least be thankful they won't fall further over the course of the round, while the same cannot be said for seventh-placed MFF.
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