The sky is the limit for Cori Gauff after the American teenager was crowned French Open girls champion at 14. That's the assessment from no less of an authority than Patrick Mouratoglou, best known for coaching Serena Williams.

The Atlanta-born teen made history when she became the youngest-ever finalist at the U.S. Open last year, losing to compatriot Amanda Anisimova.

Gauff was not to be denied a first major title on her main-draw debut at Roland Garros this month, beating fellow American Caty McNally, 1-6, 6-3, 7-6 (7-1), just a few months after turning 14.

Though Mouratoglou is best known for working with the great Williams,players of all ages, abilities and nationalities benefit from the French mentor's expertise at his state-of-the-art Mouratoglou Tennis Academy on the French Riviera.

Gauff is among the proteges who are reaping the rewards of working with the meticulous 48-year-old.

"She is only 14 years old, she reached the final of the U.S. Open juniors last year at the age of 13 — the youngest ever in the history to do that," told Omnisport in Paris. "She is fantastic, she can become a top, top player. I believe in her a lot."

Mouratoglou also coaches Chun Hsin Tseng, a 16-year-old who won the boys title on the clay in the French capital.

Five finals (including three over the last five junior Grand Slams.



Back-to-back Boys' @rolandgarros titles (2017 & 2018).



A historic double this year at #RG18.



We're shaping champions. pic.twitter.com/nqczXprPCB — Mouratoglou Tennis Academy (@MouratoglouAcad) June 11, 2018

He added of his young champions: "Both of them are fantastic.

"At every age group we have some of the best players in the world at the Academy.

""I don't see any limit on what they can achieve. They are young, they are hungry, they are talented, they are working hard and I think they have a very good environment around them. Let's start the journey and go as far as they can and not put any limits on what they can achieve."