HBO - Real Sports Frances Tiafoe

In 2003, Andre Agassi won the Australian Open and Andy Roddick won the U.S. Open.

Since then, no American man has captured a Grand Slam championship.

Of the nine U.S. players ranked in the world's top 100, the youngest is 19-year-old Frances Tiafoe. He is No. 63, and his rise to the elite level of tennis is the stuff of feel-good movies.

Tiafoe's parents came to the United States as war refugees from Sierra Leone. They settled in Maryland where his dad got a maintenance job at a tennis academy. Tiafore tagged along and worked on his game.

He turned pro in 2015 and has become the latest hopeful to be America's breakthrough champion.  HBO Real Sports has a profile in its new edition that premieres Tuesday at 10 p.m. ET/PT. Here is a preview: