LOS ANGELES — During a recent practice, Claire Liu sent an easy forehand sailing to the fence beyond the baseline and pressed a palm to her forehead.

“Smile, you’re having fun,” said Chris Tontz, Liu’s coach.

“Am I?” she said with a laugh.

She should be. Liu, 17, is currently the top-ranked junior in the world and the No. 292 player in WTA rankings. In the last three months, Liu has won two titles on the Pro Circuit, a level below the WTA Tour, and become the first American to win the Wimbledon girls’ title since Chanda Rubin in 1992. She made her main-draw debut in a WTA tournament this month at the Bank of the West Classic, where she led Nicole Gibbs, 5-2, in the third set before fading and losing in a tiebreaker in the first round.

Liu first garnered attention in 2015 when she won a Pro Circuit title in Orlando, Fla., at 14, becoming the youngest woman to win a pro tournament since Anna Kournikova in 1996. Three months later, after turning 15, she reached the final round of qualifying at the United States Open.

Despite the pressure that comes with such results, Liu is pushing back against the typical narrative of a rising teenage tennis player. Now, she has reached a crucial point in her development, choosing between going to college and turning pro.