BUG: Lv7 Heart Attack: all enemies slain but map is still not won

I have erased all remaining enemy forces, even incarcerated the three priestesses in the target room and claimed all tiles in reach, but the game won't let me win the map.

First time my imps took over the gate, second time I let my dwarves bring down the gate. Both times I slew the remaining dwarven lord and the lv10 priests with ease but the map is still running.

Guess I did not trigger the end sequence, what's gone wrong?

Did read on the net: I have to loose the map to progress further. Although it's an easy map, I managed to get overrun by dwarven-zergling-rush; but it was assessed as a common defeat, so I guess I still have to trigger the forementioned sequence before losing.

Core Information

Win 10 64bit

RAM 8 GB

CPU Intel 4770 3.4 GHz

GPU NVIDIA GeForce GTX 770

Save (after the Bug)

7 heart attack_20161215180418.meta 7 heart attack_20161215180418