NEW YORK — Sloane Stephens raised her eyebrows and with a sly smile didn't hesitate in answering the question of whether this American teenager is tennis' next superstar.
"She is," Stephens said.
Bubbly and confident, Stephens, 19, plays the part of the youngest woman ranked in the top 50 in the world. Stephens on Tuesday defeated 22nd-seeded Francesca Schiavone 6-3, 6-4 in the first round of the U.S. Open, technically an upset because the American is ranked 44th, a career best.
Then again, Stephens has advanced to at least the third round at three of her past four Grand Slam events.
"I don't have a crystal ball to see the future, but I can say that she's an athlete who has every possibility to produce some great tennis," said Schiavone, 32, the 2010 French Open champion. "First of all, she's athletic. She has long legs. She did some great sprints (Tuesday). And she can change speeds, change the height of her shots. That's important."
Her successes assure Stephens that she doesn't need to do anything out of the ordinary to beat players such as Schiavone.
"I did everything that my coach asked me to do," Stephens said. "I just really stayed within myself and tried to do my best. For me, that's a big step. If you do everything you want to do in your match, if you accomplish all your goals for today, which I did, I'm pleased, very pleased with myself. That's something that gives you confidence, and that takes you far."
Also on the women's side, Serena Williams advanced to the second round, defeating CoCo Vandeweghe 6-1, 6-1 in 55 minutes. Sister Venus, playing her first U.S. Open match since she pulled out before the second round in 2011 and revealed she had been diagnosed with an autoimmune disease, used her powerful serve to right herself and beat Bethanie Mattek-Sands 6-3, 6-1.
One Venus serve of 124 mph jammed Mattek-Sands' left index finger, shoving it into a racket string so hard she needed attention from a trainer.
"She was crushing her serves," Mattek-Sands said. "I don't think anyone's returning those, so I'm not going to beat myself up too much."
One exit of significance: 2009 runnerup Caroline Wozniacki, who began the year ranked No. 1 but has struggled and was seeded eighth, lost 6-2, 6-2 to 96th-ranked Irina-Camelia Begu. Bothered by a bad right knee, Wozniacki also lost in the first round at Wimbledon.
Andy Roddick, whose 2003 U.S. Open title was the last Grand Slam title won by an American man, beat 21-year-old American qualifier Rhyne Williams 6-3, 6-4, 6-4.
Appearing in his 13th consecutive U.S. Open, Roddick turns 30 Thursday. Asked in an on-court interview what sort of present he would like, he smiled and responded: "I just want to be around for next week. That's all I want for my birthday."
After a pause, he added: "And then we'll renegotiate."