In 2014 in Winston-Salem , he was able to qualify for a main field on the ATP World Tour for the first time in the individual competition . In the first round he met Oleksandr Nedowjessow , to whom he was defeated in two sets. A week later he received a wildcard at the US Open for both the single and the double competition , making his debut at Grand Slam tournaments . In the singles he failed in the opening round in three sets to John Isner and in doubles at the side of Kevin King also in the first round to Dušan Lajović and João Sousa in two sets. In the second week of the US Open , Giron won the American Collegiate Invitational and thus secured a wildcard for the US Open 2015 . However, this only applied to the qualification , as Giron missed the top 250 in the world rankings. This had been agreed as a condition for a direct start in the main field. He lost to Alejandro González in the first round .
He won his first title on the Challenger Tour in January 2019 in Orlando .