American teen Sloane Stephens advanced to the Round of 16 at the French Open on Friday after defeating Mathilde Johansson of France 6-3, 6-2. The world No. 70 finished her third round match with 26 winners and broke Johansson's serve seven times.

The 19-year-old's aggressive returns and agile movement gave Johansson little room to find a comfortable rhythm.  

She didn't give me any easy points,'' Johansson explained.  I had to fight for each point, each game, and, frankly, I think she was a lot tougher than I was.

Her third round performance demonstrated an aptitude on clay which many American players have failed to exhibit in years past.  When asked in an ESPN interview why she enjoys the surface so much, Stephens responded, It's just so fun--you slide around and you're doing all kinds of stuff.

Even more impressive than her effortless movement on the surface is the fact the 19-year-old is the only teenager remaining in the tournament of the eight teenagers in this year's draw.

In a sport that is now dominated by experienced veteran players, Stephens attributes her recent success to focus, concentration, and never getting away from the moment.

That concentration has helped Stephens climb steadily through the rankings since turning pro in 2009. After reaching the third round of the 2011 U.S. Open, Stephens notched impressive victories over experienced players such as Sara Errani, Anna Chakvetadze, and Ayumi Morita among others.

Stephens's game has improved by adding versatility, improving her fitness, and maintaining a superb level of concentration throughout matches, which has allowed her to move comfortably into the fourth round without dropping a set.

This, coupled with her athletic genes - her mother, Sybil Smith, was a First-Team All-American in swimming at Boston University; her late father, John Stephens was the 17th  pick of the 1988 NFL Draft and 1988 NFL Offensive Rookie of the Year with the New England Patriots - makes Stephens a promising star for American tennis.

Stephens seems unaffected by the pressure of being the hope of U.S. tennis. In her post match interview, she instead noted the surge of her Twitter followers as a source of excitement.

Stephens faces Samantha Stosur of Australia, the 2011 US Open champion, in the fourth round.