China beat Uzbekistan 3-0 in Sydney while North Korea hammered Bangladesh 5-0 also in Group B.
Both teams are yet to concede a goal at the tournament.
China took the lead on the half-hour mark when Shao Ziqin was dragged down in the box and she made no mistake from the penalty spot.
The holders, who beat Bangladesh 2-0 in their opening match, scored twice in the second half through Li Qingtong to seal their place in the next round.
North Korea - who launched their campaign with a 3-0 win over Uzbekistan - were even more ruthless against tournament debutants Bangladesh.
Twice in the first half the North Koreans thought they had taken the lead, only for VAR to rule out both goals.
The pressure from the three-time Asian champions 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 struck in the seventh minute of first-half injury time.
With the last eight in sight, the North Koreans added three more goals in the second half as Bangladesh folded.
China and North Korea will face off in the final round of pool matches to decide who tops Group B.
South Korea and Australia were already into the quarter-finals from Group A.