More than 45,000 supporters filled the Parc des Princes to watch Les Bleues cruise to a one-sided victory, with giant defender Wendie Renard scoring twice in between goals from Eugenie Le Sommer and captain Amandine Henry.
"Personally I could not have dreamed of a better start," said Renard, the tallest player in the competition, as she admitted an emotional rendition of the French national anthem had lifted the home players.
"We knew the Parc would be full, and after the 'Marseillaise' we wanted to get off to a great start and score in the first quarter of an hour."
France took the lead in the ninth minute and were 3-0 in front at half-time, having another goal disallowed for offside after a VAR review.
"We can savour this but we have not won anything yet. We need to keep our feet on the ground," she added.
For Henry, the win and her late goal were "the realisation of a dream I had as a little girl."
However, France coach Corinne Diacre was not getting carried away, as her side prepare to face Norway next, in Nice on Wednesday.
"I refused myself any emotion tonight. That will be for later on," said Diacre, who previously coached Clermont in the men's second division.
"We won but this is just one step. We have six more to go and we need to keep our feet on the ground and keep working."
Almost a million tickets have been sold for this World Cup amid hopes that the month-long tournament will be a springboard to helping the women's game really take off.
In France, broadcaster TF1 on Saturday reported that almost 10 million viewers had tuned in to watch the game, a figure it said was a record in the country for a women's World Cup match.
For Noel Le Graet, the president of the French Football Federation who has set Diacre's team the goal of reaching the final, Friday's opening match was the perfect showcase for women's football.
"A full stadium with a good atmosphere. There are not a lot of fouls in women's football, they don't roll around on the floor when they take a little knock, they don't complain. I think it is a great spectacle that deserves to be watched," he said.
He added that organisers had been surprised by the extent of the appetite from supporters for the 24-team competition.
"We have 16 matches sold out overall and we have gone way beyond what we hoped for in terms of ticket sales. The stadiums are almost all full."
The tournament continues on Saturday with former winners Germany facing China in Rennes in the pick of the matches.