Mariana Pajon on Friday became the first Colombian athlete to win two Olympic gold medals, after triumphing in the women's BMX cycling competition at the Rio Games.
"This is better than anything. It's so beautiful," said Pajon, who also took gold in the event at the London Olympics four years ago and is the reigning world champion.
"What am I made of? I am made of working hard, of sacrifice. I think smiling and happiness is the best doping you can have," she added, at an Olympics that has been overshadowed by allegations of state-sponsored doping in Russia.
Alise Post from the United States won the silver medal on Friday, while Venezuela's Stefany Hernandez took bronze.
In the men's competition, Connor Fields clinched gold for the US, ahead of silver medallist Jelle Van Gorkom of the Netherlands and bronze winner Carlos Ramirez Yepes of Colombia.
Fields is the first American athlete to win gold in BMX cycling, which made its Olympic debut in 2008.
"I cannot even describe it. It is a moment that I dreamed about since I was 15 years old," the now 23-year-old Fields told journalists after his win.
"There was a moment in the last corner that I realized I was winning," he added. "Seventy metres in front of me is a gold medal - get to the line, get to the line. I just dropped to my knees. I could not believe it."
Latvia's Maris Strombergs had been a favourite in the event after winning gold at the 2008 and 2012 Games, but he crashed out of the competition on Thursday after a collision with Britain's Liam Phillips in the quarter-finals.
Strombergs told journalists that he had complained about parts of the cycling course being too small, but that nothing was done.
"There are a lot of crashes," he said, but also added: "It is what it is. I am not complaining. I made some mistakes myself."