If Häcken had a really successful home premiere, visiting Hammarby had something of a nightmare night.
Nothing went Stockholm's way and Häcken's striker set ice cold double penalties in the first half.
Early in the second half, Häcken increased to 3-0 after the return on Johanna Rytting Kaneryd's shot went via his own player Alice Carlsson and into goal.
After just over an hour of play, Mille Gejl Jensen came 4-0.
At the end of the match, Hammarby's national team player Madelen Janogy was forced to leave with a feared injury.
The 26-year-old lay down on the grass and her right leg was wrapped tightly outside the sideline.
Janogy has been selected for national team captain Peter Gerhardsson's squad for the double World Cup qualifiers against Georgia and Ireland this April.
Shortly after the break, Hammarby managed to get a reduction to 4-1.
Hammarby remains at zero points ahead of the upcoming national team break.
Top-tipped Häcken now has four points.