Caio Bonfim of Brazil raced to silver in 1:19.09, while 2023 world champion Alvaro Martin of Spain was third in 1:19.11 to kick off the Olympics athletics competition.
The victory was Pintado's first in a global competition after he raced to silver in the 35km distance at the 2022 world championships.
The lead changed hands numerous times in a tight lead group of 15 walkers through the first 13km, but the group started to spread out at the 15km mark.
The top four had pulled away from the field by the final lap, with Pintado, wearing dark performance sunglasses and an ice-filled scarf around his neck, increasing his lead over the final gruelling kilometre.
The Ecuadorian shook two fists in celebration after crossing the finish line.
The course was a 1km loop along the picturesque Pont d'Alene and under the Eiffel Tower.
An early-morning thunderstorm had pushed back the start by 30 minutes, but by the time the walkers took to the line, the clouds had given way to blue skies and a comfortable temperature of 22 degrees Celsius (72 degrees Fahrenheit).
The Olympic race walks returned to the host city of Paris three years after the Olympic walks were held in Sapporo to beat the sizzling Tokyo heat.
While the conditions for the men's race on Thursday were far more forgiving, walkers doused themselves with water at the aid stations, and several wore chilled scarves around their necks.
