Before the hour was played, the goals had been pouring in from both directions, but the score was still tied.
Then Blackstenius entered the action. The Swede, who got the chance to start for the second time in the league this season, could score the winning goal in the 78th minute.
Blackstenius appeared in the penalty area in classic striker fashion and scored 4-3 from close range.
The goal was her third in the last five matches, and also her fifth for the season. In the 88th minute, she received applause from the away supporters when she was substituted in favor of her Swedish colleague, Rosa Kafaji. Amanda Ilestedt also got to jump in during the final minutes.
The win means that Arsenal passes Manchester City and is the new number two in the table.