Prado, 24, was the first to cross the finish line with a time of 2:24:54 at the marathon last weekend.
However, his victory was short-lived as Prado was later disqualified from the marathon this week for taking water from two men on bicycles, one of whom was his father, The New York Times reported.
The U.S.A. Track & Field rule book says only "authorized people" at official stations on the course of a marathon can provide water and other types of liquids.
"A competitor who collects refreshment from a place other than a refreshment station is liable to disqualification by the referee," the rules said.
"We were forced to disqualify a participant after it was confirmed they received unauthorized assistance from an individual on a bicycle, in violation of U.S.A. Track & Field rules and our race regulations, Garu Kutschar, the director of the Orange County Marathon, said in a statement.
"We take these rules seriously to ensure fairness and the integrity of our event for all competitors," he added.
Prado said he spent about four months training for the race and was celebrating his victory before getting a call from Kutschar, who informed him that a competitor saw him take a water bottle from someone during the race.
"The only person that could see me within range was second place," Prado told ABC News’ Los Angeles Station KABC. "You get no money or anything. You know, if [the second-place] wanted that congratulations for that first place, if he really felt like he needed it, it's just for him at the end of the day."
Prado knew that he had access to the water stations during the run but was unaware of the rules, and he was not happy with the outcome.
"I really got nothing out of it. I know I won," he added.