Donald Young was supposed to be the Next Big Thing in American tennis.
That's when Young, then 16, became the youngest player — and first African-American — to reach No. 1 in the world in juniors.
Six years later, Young, now 22, may finally be realizing the potential many tennis experts thought he initially possessed.
On Tuesday, the Atlanta, Ga. native hopes to continue his storybook run at the U.S. Open when he takes on No. 4 Andy Murray of Scotland in a fourth-round match.
"Some people have to learn from experience," Young said. "Some people can listen and do it; some people have to learn from experience. I was definitely one person that had to learn from experience."
Young said his low point came when he lost in Challenger events to players ranked as low as No. 300 in the world.
He also stirred up trouble earlier this year on Twitter, lashing out with a series of profane tweets after he wasn't given a wildcard spot in the French Open.
Still, he upped his fitness level and mental toughness by training with the United States Tennis Association in Carson, Calif., alongside fellow Americans Mardy Fish and Sam Querrey. He also hit with 14-time Grand Slam singles champion Pete Sampras.
At the Open, he's into the fourth round for the first time ever after knocking off two seeded players, No. 14 Stan Wawrkinka in five sets, and No. 24 Juan Ignacio Chela in three.
"He's talented, so he can hit winners from all parts of the court," said Murray, seeking his first career Grand Slam singles title. "He comes forward pretty well, he volleys good, he's got nice feel around the net, and he's got quite easy power which, you know, can be sometimes difficult. Guys look like they're not winding up to hit a big shot, and he can create quite a lot of power."
Young beat Murray at Indian Wells earlier this summer, his first victory over a Top-10 player.
Now Murray is seeking revenge.
"It's more sort of not so much revenge against Donald, it's more for the situation I was in there and making sure that, you know, I can kind of move on from that," Murray said.
For Young, he hopes the dream run continues with another upset. If he can pull this one off, it would be the biggest victory of his career.
"I'm playing well also," Young said. "We'll see what happens when the match comes."
Follow Adam Zagoria on Twitter @AdamZagoria.