Sirius' 4-4 draw with Mjallby on the league's return from the summer break two nights earlier meant Elfsborg had the chance to cut the gap to eight, but instead the Uppsala side are still nine points ahead after Hammarby went above Hacken on goal difference.
In doing so, Bajen not only ended a three-game losing run, but won their first match under the stewardship of Henrik Rydstrom, who replaced Kalle Karlsson over the summer. Some things never change for Hammarby, including Paulos Abraham getting among the goals. It was his simple downward header, meeting a Victor Lind cross, that gave the visitors the lead after 50 minutes.
Just under 25 minutes later, Abaraham saw a chance for his second thwarted by Isak Pettersson, only for the rebound to fall to Montader Madjed, who steered it into the bottom corner from the edge of the area.
Elfsborg were back in it in the 77th minute when a Julius Magnusson cross was powered in on the volley by Ari Sigurpalsson, but the hosts were unable to force a late equaliser and fell to just a second loss of the season.
The summer break came at the wrong time for Goteborg, who were unbeaten in three beforehand but have returned to losing ways against AIK, who have relieved some pressure by moving five points clear of today's opponents, who occupy the relegation play-off place.
Goteborg looked set to climb out of the bottom three when a curling effort from Sebastian Clemmensen put them in front just before the 30-minute mark. However, the lead lasted all of four minutes, as Taha Ayari fought off challenges before slotting a neat ball through for Johan Hove to finish.
And 14 minutes from time, Ayari was at it again, feeding another through ball, this time to Axel Kouame, who sealed all three points for AIK by keeping his composure and slotting the ball between the goalkeeper's legs.
Pulling themselves three points clear of the bottom three were Kalmar, who picked up a fourth home win in succession by cruising past Orgryte, the side bottom of the table and still with one win all season.
It took less than three minutes for Charles Sagoe Jr to lay the ball back for Carl Gustafsson to sweep into the bottom corner to put the hosts ahead, and less than two second-half minutes for Arsenal loanee Sagoe to do the same for Abdussalam Magashy, who finished from the middle of the 18-yard box.
Sagoe was taken off with 10 minutes to play, but four minutes later Marius Soderback was occupying his left-wing position and sliding the ball across to give Rony Jansson a simple finish to cap off a perfect afternoon for Kalmar.