Her compatriot Liz Akama took silver, while Brazil's Rayssa Leal claimed bronze.
The top-ranked competitor heading into the Olympics, Yoshizawa held her arms out wide after sliding down the rail in the highest-scoring attempt of the best-trick stage of the competition that put her out of reach.
Akama, who had a slim lead heading into the best tricks, nailed a sublime 270 switch front board on her opening attempt but could not improve on that effort.
The rowdy crowd at the urban park was a ringing endorsement of the sport, just three years on from its introduction to the Olympic programme at the COVID-delayed Tokyo Games.
Yoshizawa had the best overall score of the opening heats and showed no loss of momentum in the final, where she made terrific use of the skatepark's 18 features in two pristine runs.
She trailed Akama by a few points going into the five tricks and unleashed the best moves she had in her arsenal to try to wrest the lead back, with a fine kick flip front board on her second trick.
Yoshizawa had her highest-scoring trick (96.49) on the fourth try.
The 16-year-old Leal had the full support of a large Brazilian contingent in the crowd as she attempted to improve on her Tokyo silver.
But after a couple of tumbles she appeared happy to take bronze with a kick flip front board on her final trick of the day, as the crowd chanted her name.
Three teenagers on the podium would seem shocking at most other Olympic events, but not so at the women's street, where the next generation has a firm grip on things, with only a handful of the 22 Paris competitors aged 20 or older.
School-age skaters flew through the course against the backdrop of Paris' historic landmarks, as the Eiffel Tower, Grand Palais and Arc de Triomphe loomed on the horizon.
The sport lifted television ratings when it was added to the programme in Tokyo, as organisers work to bring a younger audience to the Olympics.
The men’s street competition is set for Monday, after rain on Saturday forced a postponement.
