Arsenal Women will have to overcome a 1-0 deficit against BK Hacken in order to reach the Champions League group stage.
The Gunners hit the crossbar twice on a frustrating night in front of goal, and conceded to Tabitha Tindell in the 77th minute.
Former Hacken forward Rosa Kafaji smashed a shot onto the crossbar in the first half as Arsenal toiled in front of goal.
Beth Mead had an effort brilliantly saved from close range by Jennifer Falk early on in the second half.
Jonas Eidevall's side struggled to break Hacken down and should have gone a goal down when Clarissa Larisey rounded Manu Zinsberger but could only find the sidenetting.
Arsenal were hit on the break again by Hacken and Tindell kept her composure to lob Manu Zinsberger.
Substitute Frida Maanum headed onto the crossbar late on.
The Gunners take on Manchester City in their opening Women's Super League fixture on Sunday lunchtime before the return leg against BK Hacken.