Group C leaders Japan, champions in 2014 and 2018, cut through India's hapless defence with ease while the south Asian side failed to have a single shot in the game that was played predominantly in India's half at Perth Rectangular Stadium.
Japan overwhelmed India in the first half and were 5-0 up at halftime with a superb curling effort from Yuzuki Yamamoto in the fourth minute, a Yui Hasegawa goal, a brace from Miyazawa and a Kiko Seike penalty.
With a comfortable lead, Japan made three changes at halftime but they did not relent as substitute Riko Ueki scored twice in three minutes before completing an 18-minute hat-trick after Maya Hijikata also got on the scoresheet.
Miyazawa capped off the rout by completing her own hat-trick in the 81st minute, sealing an 11-0 scoreline that highlighted the gulf in class between Asia's highest-ranked team in the world and their hapless opponents 59 rungs below them.
In the earlier Group C match in Perth, Taiwan's Su Yu-hsuan scored with a first-half header to give the three-times Asian champions the lead, with both sides otherwise struggling to find cohesion in attack before the break.
Vietnam, quarter-finalists at the previous edition, had nine attempts on goal but none on target, while Taiwan stayed organised at the back to preserve their advantage.
A late VAR review for a possible penalty for Vietnam did not yield a decision and Taiwan moved into second place in Group C on three points.