Carapaz bided his time on the 234-kilometre course, before joining American Brandon McNulty in an attack with 25 kilometres to go.
The Ecuadorian worked with McNulty to keep a chasing pack led by Wout van Aert at bay and, later on the Fuji Speedway, surged clear with five kilometres to go.
Despite boasting a Giro d’Italia title and third-placed finish at this year’s Tour de France, the 28-year-old revealed nothing compared to his Olympic accomplishment.
“There is no comparison,” Carapaz said. “This is the best thing that could have happened to me in my life.
“Back in my country right now, they’ll be going crazy.
“It’s the second gold medal in our history. If I’m not mistaken, it’s 24 years since the last one, so it’s special.
“It’s special because it’s the first in this sport and I think it’s the sport most people follow in my country.
“We’ve had a lot of good achievements, some good titles, and now another one with this gold medal.
“It’s incredible.”
Race walker Jefferson Perez is the only other Ecuadorian to win an Olympic medal – gold in Atlanta ’96 and silver in Beijing ’08 – and Carapaz was overcome with emotion at hearing the Ecuadorian national anthem ring out at the Games again.
“It is incredible to see your flag as the top one, and to have this medal,” he added. “It’s sensational.”
