Lisa-Marie Utland fired through the hands of keeper Tochukwu Oluehi to make it 2-0 before an own goal by Osinachi Ohale compounded Nigeria's misery.
Norway scored three first-half goals on the way to an easy win over Nigeria in their opening Group A game at the 2019 Women's World Cup in Reims.
The 1995 world champions took the lead when Guro Reiten's shot deflected off Onome Ebi into the net.
Lisa-Marie Utland fired through the hands of keeper Tochukwu Oluehi to make it 2-0 before an own goal by Osinachi Ohale compounded Nigeria's misery.
Norway are level on points with hosts France, who they face on Wednesday.
Ingrid Hjelmseth, Norway's 39-year-old goalkeeper, had little to do as Nigeria struggled to carve out chances.
On a bad night for the African champions, defender Faith Michael was carried off on a stretcher after being caught by team-mate Oluehi.
Norway are chasing their first world title for 24 years and Martin Sjogren's side certainly laid down a marker as they breezed past the group's lowest ranked team at Stade Auguste-Delaune.
They are without Ada Hegerberg, the first Women's Ballon d'Or winner, who has refused to play for the national side since 2017 after taking a stand against what she describes as a lack of respect for female players in the country.
Yet with a team featuring Chelsea duo Maria Thorisdottir and Maren Mjelde, they sealed the points with three goals in the space of 20 minutes.
Reiten combined with Caroline Hansen to open the scoring, her shot deflecting off the arm of Ebi, the first African to play in five World Cups, on its way into the net.
Utland doubled the lead with a powerful shot which Norway celebrated with a fake team selfie before Ohale's attempted clearance from Isabell Herlovsen's cross ended up in her own net.
While the Super Falcons now face a battle to stay in the tournament, Norway head to Nice to face hosts France in buoyant mood.
"When it comes to sport, never ever give up. We have to fight for 180 minutes more, plus added time. A game can change in the last minute so we will work very hard for it and I can promise that we'll never give up," said the Nigeria boss, Thomas Dennerby,
Nigeria defender Onome Ebi said after the match: "We're going to go back and look at our mistakes and work on them. The second game will be better than the first, we've learned so much from this first game and we'll come back."
Next, Norway head for Nice for their second group game where they face hosts France on Wednesday (20:00 BST), while Nigeria are in action against South Korea in Grenoble on the same day (14:00).