Correction: An earlier version of this article misstated the last name of a chess grandmaster. He is Ben Finegold, not Ben Fineman. This version has been corrected.

Jennifer Yu, 12, of Ashburn, competes in the World Youth Chess Championships in Durban, South Africa, in September. Yu won the world title in the girls 12-and-under group, the first American girl to win a world title in 27 years. (Reint Dykema)

Although Jennifer Yu started playing chess in first grade in California, her parents didn’t pay much attention to her progress. “My husband and I did not take her chess learning seriously at all,” said her mother, Yan Zhang, “and did not support her much other than taking her to a weekly group lesson and occasional tournaments for kids.”

But shortly before her family moved to Northern Virginia in 2011, Jennifer’s coach took her parents aside. “Jennifer is really talented and has huge potential,” he told them. “You have to find her a coach over there” in Virginia.

They did. And Jennifer’s talent blossomed. Then last month in Durban, South Africa, the 12-year-old Ashburn resident became the first American girl in 27 years to win a title at the World Youth Chess Championship, going undefeated in 11 matches. She is rated a “national master” by the U.S. Chess Federation and, according to chess expert and grandmaster Susan Polgar, Jennifer is probably one of the top 500 chess players in the country. At 12.

“Jennifer Yu stole the show at the 2014 World Junior Championship,” grandmaster Ben Finegold wrote on the U.S. Chess Federation Web site, noting that she won nine of her 11 matches and scored draws in the other two. “I was most impressed with her last round game,” Fineman wrote, “where, after already clinching Gold, she simply crushed her opponent.”

Jennifer, an eighth-grader at Trailside Middle School in Ashburn, isn’t obsessed with chess. She likes playing sports, reading, and listening to singers Taylor Swift and Bridgit Mendler. But not TV. Her mother said she sometimes has to remind Jennifer to practice her chess an hour a day.

Yu’s rating through FIDE, the World Chess Federation, ranks her as a “women’s FIDE master.” She is the 17th-ranked female of any age in the United States. (Tom Jackman/The Washington Post)

Still, Jennifer feels as if chess clicked for her around fifth grade. “I started improving my opening,” she said, mostly by memorizing certain move sequences, and her ranking shot up. “And then it started getting interesting,” she added.

Interesting as in starting to win tournaments beginning in 2011, then in 2012 sharing the national championship for girls 10 and younger. Her first win was at a tournament in Phoenix run by Polgar, who has been pushing for more girls and women to succeed in chess.

“Chess is still largely male-dominated,” said Polgar, who runs the Susan Polgar Chess Institute of Excellence and was the first woman to earn a men’s grandmaster title. She has coached four straight men’s collegiate national champion teams. In the case of Yu’s victory, she said, the United States sent “a delegation of over 70 kids [to the world championships] and she was the only one to win the gold, so that’s really remarkable.”

Records show, and Polgar confirmed, that Jennifer was the first American girl to win a youth world title since 1987. “So we’re getting there, slowly but surely,” she said.

Jennifer was born in Ithaca, N.Y., while her parents were working on their PhDs at Cornell University. Yan Zhang and her husband, Zhiheng Yu, are scientists at the Howard Hughes Medical Institute’s Janelia Farm Research Campus in Ashburn, where a colleague last week won the Nobel Prize in chemistry. They have two other children, Larina, 9, and Oliver, 1.

Although she spends at least an hour a day on chess and takes weekly instruction via Skype from grandmaster Larry Christiansen, it is the tournaments that hone and improve Jennifer’s skills, she and her parents said.

“After moving to Virginia, we started to take her to many chess tournaments,” Zhang said. “One thing we found is the more games she plays, the better she gets. . . . In many games she was in a losing position, but she kept playing, staying calm and eventually found a way to equalize or even win.”

Jennifer first qualified for the world championships as a 10-year-old in 2012 and traveled to Slovenia. “I played okay,” Jennifer said. She finished 11th out of 120.

Last year, Jennifer entered the North American Youth Chess Championship in Toronto and won the 12-and-under division. That earned her another shot at the world championships, in the United Arab Emirates, where “at first I did quite well,” she said, but wound up coming in fourth. She had more success in tournaments this year, including winning a national invitational in Orlando in July, leading to her third world championship trip in September.

Of the 80-girl field, Jennifer was one of the top-rated players. “This year I played like I usually play,” she said, “instead of terrible moves that made me lose.” She said she doesn’t like to use scripted openings or planned attacks. “I can play any style I get into; I can play position or aggressive attacking,” she said.

Each tournament has 11 matches, and soon Jennifer was playing on “Board 1,” indicating the field leader. After 10 matches, she had won eight, tied two and had wrapped up the title. But “I still had to win that game,” she said. “I don’t like giving away points.”

She didn’t. She won again, getting 10 of a possible 11 points and winning a girls tournament for the first time since 11-year-old Yvonne Krawiec and 8-year-old Susan Urminska in 1987.

Jennifer also raised her points rating through FIDE, the World Chess Federation, to 2,112, which makes her a “women’s FIDE master.” Her U.S. Chess rating is close to 2,200, which qualifies her as a “national master.” According to FIDE, Jennifer is the top-rated 12-and-under girl chess player in the world and the 17th-ranked female of any age in the United States.

“Jennifer has all the key ingredients of a top player,” Christiansen said. “She has great vision of the 64 squares, tactical alertness, superior memory, will to win and, most especially, strong mental staminaShe will no doubt reach the grandmaster level if she stays with the game.”

Jennifer said she plans to stay with it. “I love it; it’s a lot different from any other game,” she said. “I want to see how far I can go.”

But she’s not sure whether she wants to turn pro. She pointed out that her mother has a medical degree and a PhD but never practiced medicine. “I can finish the doctor thing,” she said. “It’s good to help people. But I’m not sure now. I’m only 12.”