Djurgarden made six changes to the side that lost their European Quarter-Final to SK Rapid on Thursday, but take nothing away from the Hammarby performance, as the designated home side at the 3Arena ran out 2-0 winners.
One of the visitors' changes - goalkeeper Filip Manojlovic - was at fault for the opening goal late in the first half, spilling a cross at the feet of Paulos Abraham, who squared to Jusef Erabi to tap home.
The second half had few clear-cut opportunities, though it was the Bajen who looked more likely to score the crucial second goal. Seven minutes from time, it arrived, when a swift attack was rounded off by Abdelrahman Boudah collecting Erabi's precise through ball and finishing well.
Djurgarden will write this derby defeat off for its unfortunate timing in between their two UECL last eight legs, while Hammarby will drink in the fact it has taken them to the summit with nine points from a possible nine, eight goals scored and zero conceded.
Monday night's meeting at Strawberry Arena gave two more teams the opportunity to remain on maximum points and challenge Hammarby for first place, but AIK's match with Malmo ended 0-0.
In a match of few big opportunities, the best arguably fell to John Guidetti early in the second half, but he did not catch the strike as he would have wanted and it trickled wide of the post to give Malmo a let off.
It's a second clean sheet apiece for the sides who now sit second and third, respectively, on seven points each.
It looked like we were not going to see a goal in either of Monday's matches, until Halmstad struck late to beat new boys Oster, 1-0.
The home side had been beaten in their first two matches without scoring, but were good value for all three points to lift themselves off the bottom of the standings, having six shots on goal to Oster's one.
That was even though they had to wait until the 94th minute for the winning goal, which came courtesy of Bleon Kurtulus' looping header from a free-kick. Oster drop to ninth, staying on three points.
Relinquishing top spot are newly-promoted Degerfors, who were brought back down to earth with a 2-0 loss to GAIS in Gothenburg.
And it was a rocket that brought them back down - a rocket into the top corner in the 21st minute, appropriately from GAIS number 21, Axel Henriksson, who chested the ball down, waited for it to sit up nicely and hammered it into the postage stamp from 25 yards.
GAIS doubled the lead just before half-time when a neat through ball found Ibrahim Diabate, who shrugged off his marker and coolly slotted the ball home, sealing a first win of the season for the Mackerels.
After back-to-back losses, Brommapojkarna have also sealed their first three-point haul of the campaign, doing so in fine style, going to Sirius and winning 0-3.
The home side were made to pay for not taking their opportunities in the first half, as nine minutes into the second, a Daleho Irandust header back across the danger area was nodded home by Ezequiel Alladoh.
Eight minutes from time, Irandust left the Sirius defence for dust, going on a mazy run culminating with his strike hitting the post, only for the rebound to fall kindly for Anton Kurochkin, whose effort clipped the other post and went in.
In added time, another Kurochkin shot trickled in under goalkeeper Ismael Diawara to round off a big win for the Bromma boys, who are now level with Sirius on three points from three matches.
Having begun the campaign with a 4-0 thrashing by Hammarby, Goteborg are finding their feet in 2025, recording back-to-back 1-0 wins, the latest of which came at Varnamo.
The certainly rode their luck in the first half, as the home side had more shots and more on target, but crucially, IFK's only goalbound effort of the first 45 minutes crossed the white line.
Just as with their win against Halmstad last time, it was Max Fenger who got it, meeting a Ramon Lundqvist cross with his head, though Varnamo goalkeeper Viktor Andersson should have done better.
It was a third straight loss for Varnamo, who sit bottom of the pile.
Another side to record a maiden victory of the campaign were Elfsborg, who downed Norrkoping 2-0 at Boras Arena.
The Comrades' goalkeeper David Andersson was keeping them in the game with some marvellous saves early on, and he even got something on Taylor Silverholt's initial effort in the 33rd minute, but could do nothing to stop the same man's follow up.
Norrkoping came within a post-width from a late equaliser, but when throwing bodies forward in added time, left themselves exposed and allowed Frederik Ihler to finish off a counter attack. Elfsborg move onto four points as Norrkoping remain on the three they earned on the opening day.
Hacken are another side who have lost twice since a win on matchday one, as they were beaten 0-3 by Mjallby, who remain unbeaten.
The breakthrough came in first-half stoppage time, when a strike from wide out was batted down into the path of Axel Noren, who made no mistake on the follow-up.
Mjallby took the game away from their hosts with two second-half goals in quick succession - Abdoulie Manneh had time to pick his spot when receiving a square ball, then, three minutes later, Nicklas Rojkjaer took it upon himself to cut in from the left and curl a delightful ball past the goalkeeper.
Having begun with consecutive draws, Mjallby are into the top half of the slowly forming table, on five points.