The home side outscored the Manusina by six tries to two in Lautoka on Saturday, with fullback Aloesi Nakoci scoring two long-range efforts in the first half and first five Lavena Cavuru finishing with two tries, four conversions and a penalty goal for an impressive 21-point haul.
Fijiana XV captain Sereima Leweniqila said, despite an impressive scoreline, the game was far from easy.
"They were a tough team - we knew they were going to come out hard," she said.
"It was a tough game: the first 10, 20 minutes they were really hard up on us but we just stuck together and I would just like to thank them for the game, it was a good one."
The Fijiana will be competing in a Rugby World Cup for the first time in 2021 and Leweniqila admitted the achievement was "still sinking in".
"It's history in the making," she said.
"Hats off to the girls for their hard work and our family that has been with us throughout the journey, they've been coming throughout to most of our games. So, just thank you for the support - their cheers as well encourage us to go hard on the field."
Samoa captain Nina Foaese said her team had high expectations going into the match and it was a disappointing loss.
"It was a hard match playing against Fiji today and they came out wanting it more," she said.
However, the Manusina still have one more chance to qualify for the 2021 World Cup in New Zealand.
Papua New Guinea will face Tonga in the new year, with the winner of that match to playoff against Samoa for a place in the final Rugby World Cup repechage tournament.
Photo Oceania Rugby