But Wales did find their composure, frustrating Denmark and threatening with clever movement and counter attacks.
With Fishlock back in the side after injury and gaining welcome minutes ahead of the Euros, Wales looked a team comfortable in their roles, with captain Angharad James also impressing.
And a superb last-ditch block from Josie Green on Harder – and further smart goalkeeping from Clark – late on ensured they were deservedly level at the interval.
But no sooner had they re-emerged, Harder made the most of a missed tackle in the middle of the Wales half and ghosted into the area, weaving wide to the right and then angling a shot past Clark.
With the 0-0 draw between Italy and Sweden in the group's other game meaning Wales had to win to avoid relegation, they did throw bodies forward in an attempt to force the issue with Hannah Cain looking sharp from the bench.
But in a compliment to Wales' progress, Denmark dropped deep and denied Wales their hopes of a comeback.
And while Wales will again take heart from pushing a top side as they took another step to the Euros, the wait for that statement win goes on.