One of the title favourites in Australia, North Korea launched their campaign with a 3-0 win over Uzbekistan and were even more ruthless against tournament debutants Bangladesh.
Twice in the first half at CommBank Stadium outside Sydney the North Koreans thought they had taken the lead, only for VAR to rule out both goals.
Bangladesh were beaten 2-0 by China in their opening match and it was only a matter of time against the North Koreans.
The pressure finally paid off in first-half stoppage time when Myong Yu Jong slotted home a penalty to go with her hat-trick against Uzbekistan.
North Korea doubled their lead two minutes later when Kim Kyong Yong made it 2-0 in the seventh minute of first-half injury time.
With the quarter-finals in sight, Kim, Chae Un Yong and Kim Hye Yong added goals in the second half as Bangladesh folded.
Holders China face Uzbekistan in the same Group B later Friday.