The Manusina led 43-0 at half-time in Lautoka and ran in nine tries to two over the Palais, who they only beat by 11 points last year, with fullback Saelua Leaula and right wing Apaau Mailau scoring three apiece.
Captain Nina Foaese said it was a great start to the tournament.
"It was good. We achieved what we wanted in this game. We've just got to get quicker on attack and set up on d(efence), just reaction," she said.
PNG captain Margaret Naua said her side needs to improve their defence, line-speed and ensure they work as a team.