With Djurgarden potentially suffering a hangover from their UEFA Conference League semi-final first leg defeat to Chelsea with the second leg to come, they were there for the taking for AIK.
But they found themselves behind midway through the first half after a moment of madness from Sotirios Papagiannopoulos, as he shoved Tobias Gulliksen to the ground of the ball inside his own area.
A penalty was awarded, which Marcus Danielson dispatched to give the home side the lead.
Djurgarden were edging towards just a third league win from their first six, but things took a turn 10 minutes from time when Miro Tenho was sent off for a second bookable offence.
The 10 men only held out for three minutes, failing to clear a cross into their box before the ball was laid off to Anton Saletros, who buried the chance.
AIK were unable to force a winner, and though they stay unbeaten this season their three-match winning run is over, as the Iron Stoves move onto eight points.
Joining AIK on 17 points but taking top spot on goal difference are Mjallby, who needed one goal at home to see off Goteborg.
After a bright start, the visitors' goal seemed to be living a charmed life until Mjallby finally found a way through after half an hour, when Elliot Stroud turned an overhit cross back across goal which was tucked home neatly by Nicklas Rojkjaer.
IFK failed to pose much of a threat for the proceeding hour and saw their two-match unbeaten run end.
A goal difference of +11 compared to AIK's +6 sees Mjallby - a club who has never won the Allsvenskan - go top of the pile as we near the quarter point of the season.
There was a shock on Monday night as Malmo were beaten 2-1 at home by Brommapojkarna - their first Allsvenskan loss at Eleda Stadion since a 1-0 defeat to Sirius on 27th July.
The home side were creating wave after wave of attack in the first half, only to be thwarted each time by the visitors' goalkeeper, Davor Blazevic.
The inevitable then happened early in the second half, as the Bromma Boys scored twice in the first six minutes.
First, Ezekiel Alladoh used his strength to hold off a challenge and finish well, then, Malmo got caught on the break and Daleho Irandust had time to pick out the bottom corner from the edge of the box.
Malmo hit the post and had chances scrambled off the line before they eventually pulled a goal back seven minutes from time through Lasse Johnsen, but it wasn't enough to prevent a rare defeat on home soil and slip to fifth, two places and one point above BP.
Also on Monday, Elfsborg got back on track after defeat to AIK with a 2-0 win over GAIS, recording their fourth win in their last five.
The breakthrough came late in the first half when the Gothenburg side didn't deal with a ball into their area and Taylor Silverholt had space to tee up Frederik Ilher.
Before the hour mark, Elfsborg doubled their lead - Silverholt was again the provider, nodding the ball across to Terry Yegbe, whose hooked finish sailed into the back of the net. Elfsborg sit fourth, two points ahead of Malmo, while GAIS are 12th and four matches without a win.
Hammarby remain third in the table with a comfortable 3-0 victory away at Oster.
The points were wrapped up before half-time after Paulos Abraham broke the deadlock midway through the first half, before Nahir Besara struck twice before the break, keeping the newly-promoted side in the bottom three.
The other newcomers, Degerfors, are enjoying a much better return so far, hitting double figures in terms of points with a 1-1 draw at home to Sirius.
Both goals arrived in the first half in this match, too - Marcus Rafferty put the hosts ahead on 22 minutes, but six minutes before the break, Leo Walta levelled matters for Sirius, who have drawn 1-1 in three of their last four.
Despite playing over 50 minutes with a man advantage, Varnamo still haven't picked up a point this season, losing 4-2 to Halmstad at the weekend.
Filip Schyberg had already put the hosts ahead before Gabriel Wallentin was dismissed, but two Naeem Mohammed goals either side of half-time put the 10 men in control, before Yannick Agnero added a fourth before the hour mark.
Varnamo pulled two back, courtesy of Johnbosco Kalu and Ajdin Zeljkovic, but it was too little too late for the visitors who stay rock bottom, as Halmstad climb out of the bottom three.
Finally, strikes in either half from Srdan Hristic then Julius Lindberg meant Hacken overtook opponents Norrkoping and moved into the top half with a 2-0 away win.
Follow the Allsvenskan on Flashscore.