Biles, the most decorated gymnast of all-time, earned the United States their fourth Olympic gold in the women's team event with dazzling performances on all four apparatus.
The American has been on what she described as a "redemption tour" at the Paris Games after she shocked a global TV audience by suddenly withdrawing from the team final in Tokyo suffering from the "twisties", a condition involving temporary loss of spatial awareness experienced by gymnasts while performing high-difficulty elements.
"I started off with therapy this morning and ... I was feeling calm and ready," the 27-year-old told an overflowing press conference at the Bercy Arena.
"As soon as I landed vault, I was like 'oh yeah, we're definitely going to do this'."
With the crowd rallying behind Biles and her teammates in the absence of the French team that failed to qualify for the final, the United States finished with a total of 171.296, an impressive 5.802 points ahead of second-placed Italy.
While the Italians won their first women's Olympic team medal since the 1928 Olympics, an incredible, high-flying vault by Rebeca Andrade helped Brazil to land the bronze, their first ever medal in the discipline. Britain finished fourth.
Biles said it was too soon to reflect on her legacy and was surprised to hear from a reporter that she has now won a jaw-dropping 38 world and Olympic medals combined.
"I'm doing what I love and enjoying it, that's all that matters to me," she said.
"Yes, it's amazing but I don't think I'll truly understand the depth of it until I walk away from the sport."
Biles, who was competing with her left calf taped after suffering a muscle strain during Sunday's qualifying competition, started her bid for the first of a possible five gold medals in Paris on the vault.
She powered down the runway before soaring high into the air while executing the Cheng vault to earn 14.900 points.
She then glided through her uneven bars routine with ease to the delight of the 15,000 fans packed into Bercy Arena, who serenaded her with chants of "USA, USA, USA!". She was awarded 14.400.
BILES, 'A DIFFERENT PERSON'
The star-studded crowd that included tennis great Serena Williams and the most successful Olympian ever, swimmer Michael Phelps, also roared their approval when Biles' teammates Sunisa Lee and Jordan Chiles completed their equally impressive displays on the bars by nailing their dismounts.
After falling flat on the mat during the warm-up, Lee -- the defending all-around Olympic champion -- stuck her landing on the uneven bars, earning 14.566 points, the highest score among the three Americans to perform on the apparatus.
Chiles, who had been solid on every apparatus during qualifying, fell off the balance beam in the final, causing gasps of disbelief throughout the arena.
Her faux pas, which resulted in a score of 12.733, was quickly forgotten thanks to a gutsy performance by Lee.
The 21-year-old never wavered on the 10cm wide apparatus as she executed a number of risky elements while flipping and somersaulting along the balance beam. Her score of 14.600 brought the United States back on track.
Biles moved through her action-packed beam routine with panache, with her only blip being a slight break on a free cartwheel.
An electrifying floor exercise routine by Chiles left the crowd hollering as she completed her double layout tumbling pass. Her elation as she struck her final pose was clear for all to see as she pumped her fist vigorously while walking off the mat.
Competing last on the floor, Biles exuded confidence as she held a captive audience while performing her gravity-defying tumbling passes. She earned 14.666 points to seal the U.S. victory, sparking joyous celebrations around the arena.
After Biles' final score flashed up on the giant screen, the triumphant American quintet that included Jade Carey and Hezly Rivera rushed onto the floor with a giant American flag as thousands of fans in the stands reached for their cell phones, determined to capture the moment.
"You can definitely tell that she's a different person from Tokyo than she is now," said Chiles, who was part of the silver medal-winning U.S. team in Tokyo and is one of Biles' closest friends.
Biles' only real misstep of the night came before the competition had even started. Wearing a white Team USA tracksuit, she appeared so focused on the task at hand that she emerged from the tunnel and headed straight towards the team's bench instead of pausing for the team's introduction by venue announcers.
After being stopped in her tracks by her teammates, a sheepish Biles took a few steps back, and beamed a big smile as the crowd let out a deafening roar when her name was announced.
