Five wins in a row for Djurgarden had seen them pull clear of the chasing pack in the race for the top three, but that race is truly alive again after they were beaten by their nearest challenger, Elfsborg, who remain in fourth and now just four points behind the Stockholm side.
Elfsborg went ahead late in a first half which they had been the better side - the hosts were unable to clear a corner which fell to Rasmus Wikstrom, whose shot deflected on its way through the crowd, making it difficult for goalkeeper Jacob Rinne, though he would have expected to do better, as he spilled the ball into his own net.
Rinne would have been happier than most to see his teammates cancel out that goal 20 minutes into the second half, when a cross curled to the back post was headed across goal by Kristian Lien, and Jacob Une stretched to meet it on the half-volley and bundle it over the line via another deflection.
But deflections and mistakes played no part in the winner, which Elfsborg found inside the final 15 minutes when Alexander Jensen got to the byline and cut it back for Simon Olsson to sweep first time high into the net and beyond the reach of Rinne.
It's three wins in the last four now for Elfsborg, while Djurgarden remain 10 points behind leaders Sirius.
Djurgarden also slipped back to third place as Hammarby regained their role of Sirius' nearest challenger with a narrow win at Degerfors, who remain 14th after losing four of their last five without scoring.
The only goal came in the first minute of the second half, and poor goalkeeping was again in the spotlight - Montader Madjed's shot from outside the area appeared to bounce off Matvei Igonen and land at the feet of Paulos Abraham, who nestled the ball in the bottom corner.
Successive wins have kept Bajen eight points shy of Sirius, with eight rounds left after the extended international window. Degerfors are inside the bottom three on goals scored.
Despite defeat, Degerfors have moved closer to safety thanks to Hacken's thrashing of Kalmar, who remain in 13th by virtue of scoring 21 goals this season to Bruket's 19. It's a first win in four for Hacken, who stay fifth and are five points behind Djurgarden.
Three minutes in, the ball was pinballing around the Kalmar box before Gustav Lindgren swept it home, and with 10 minutes of the first half remaining - just seconds after Melker Hallberg missed an open goal to equalise - Lindgren made it two when Julius Lindberg intercepted a poor pass from the goalkeeper and put it on a plate.
And with only three second-half minutes played, Lindgren completed his hat-trick when Olle Samuelsson played a delightful low cross from the left, giving the striker a simple finish that takes him to 12 for the season, with all of his last nine goals coming as part of braces or hat-tricks.
Getingarna continued to have joy from crosses as Adrian Svanback headed in Brice Wembangomo's centre to make it four, and the rout was completed with over a quarter of the match to play, as Svanback turned provider with a neat pass inside for Lindberg to bury.
After one win in their first 18 matches, Halmstad have won two of their last four and moved within five points of safety despite remaining bottom of the pile, beating an AIK side who have taken just two points from their last four outings.
The home side edged a goalless first half, but needed only wait three second-half minutes to earn their reward, as Rami Kaib fizzed in a low cross from the left and an outstretched Omar Faraj to finish.
But AIK had had their chances too and grabbed a deserved equaliser soon after when Mads Thychosen's deflected cross sat up nicely for Johan Hove to volley past the goalkeeper.
Yet in the 90th minute, Halmstad won it when Marvin Illary ran onto a through ball and powered the ball across the six-yard box for Malte Persson to apply the simplest of finishes. HBK now sit just a point behind Orgryte, while AIK drop to eighth and lose further ground in the European battle.
Mjallby's relegation worries are not over yet as they remain three points clear of the drop having suffered their first defeat since Andreas Brannstrom took over, while GAIS ended a two-game winless run in style.
The home side failed to take early opportunities and were punished in the 13th minute, when goalkeeper Robin Wallinder punched the ball to Joackim Fagerjord, who chipped the ball delightfully over the 'keeper from over 20 yards out.
Early in the second half, GAIS doubled their lead when Nikola Vasic steered home a low Dennis Collander cross, and five minutes later Vasic completed a brace by powering a loose ball into the roof of the net after Mjallby again failed to deal with a ball in from the right.
It's now six without a win for 12th-placed MAIF, with GAIS two places but eight points further clear.
