A 17-year-old from Northern Virginia became the first teen to win the U.S. Women’s Chess Championship in nearly 20 years.

“It feels pretty good. I never expected it would happen,” said Jennifer Yu of Ashburn. “It’s something you dream of but you never actually think you’ll do it.”

Chess experts said Yu dominated the tournament, held in St. Louis last month, and clinched the national title with a round to spare — a pinnacle of achievement that puts her in elite company among the nation’s chess players. The top spot also came with $25,000 in prize money.

“She blew the competition out of the water,” said Jennifer Shahade, a two-time U.S. women’s champion, who is a commenter and writer on competitive chess. “Her performance is one of the best I’ve ever seen in U.S. women’s championships.”

Shahade said the fact that Yu won “so many games against professional adults, as well as girls, is just really incredible. Jennifer’s basically playing at the professional, grandmaster level at just 17 years old.”

The last teenager to win the U.S. Women’s Chess Championship was Elina Groberman in 2000. Yu will go on to represent the United States in the Women’s World Cup of chess next year.

It is not Yu’s first taste of chess success.

In 2014, she won the gold medal in the girls’ 12-and-under group at the World Youth Chess Championship in South Africa, making her the first American girl to win a world title in 27 years. She went undefeated in 11 matches in South Africa.

Yu began winning tournaments and national competitions in 2011. Even before her most recent win — her fifth time competing at the event — the World Chess Federation ranked her No. 14 among female players under age 18 in the world.

“She’s shown she’s part of the elite pack,” said Robert Hess, coach of the U.S. Women’s Olympiad team.

Yu, a junior at Stone Bridge High School, learned to play chess at 7 and joined a club at her elementary school. Her parents, both scientists, said they did not focus too much on her performance until a coach told them about her talent.

Yu recalled feeling pressure at a tournament when she was 13, which she attributed to the cameras and live commentary. That experience helped to shape her strategy, which is to “focus and block out everything else,” especially when there is a lot of competition.

“I put so much pressure on myself, and I just did horrible,” she said. “I ended up last. I would look at every move and make sure it was right.”

Yu said she practices every day for at least an hour, in addition to juggling homework, running for exercise and playing the piano.

Shahade described Yu as modest and hard-working, with an “incredible fighting spirit and tactic.”

“If her opponent misses an opportunity, she pounces on it immediately,” Shahade said. “She never gives up.”

Even as Yu knew she was going to win the U.S. Women’s Chess Championship and had another round to play, Shahade said, the player stayed calm and focused. At last year’s event, Shahade noted, Yu had a rough first half of the tournament, then was undefeated in the second half.

“Usually if people do bad in the first half, they don’t come back,” Shahade said. “But she’s someone who has great character and realizes that every game is distinct.”

Shahade added: “She’s mature beyond her years, and she’s super awesome.”