NEW YORK -- Japan's Kurumi Nara eliminated 2004 US Open champion Svetlana Kuznetsova 6-3, 3-6, 6-3 on Thursday night to reach the third round at Flushing Meadows for the first time since 2013.
It was the first victory in nine matches against opponents ranked in the top 10 for Nara, who is No. 116.
"Biggest win of my career," she said.
Nara has never been past the third round at any Grand Slam tournament.
She arrived in New York having a rough season, failing to qualify at any of her past three events. She also was 4-11 in 2017 before this week.
But Nara broke in six of Kuznetsova's 13 service games and was steady down the stretch.
"I was nervous," Nara said, but figured that her decision to play aggressively and try to move into the court as much as possible helped her.
The No. 8-seeded Kuznetsova's exit means five of the top eight women in the field are already gone before the third round. She joins No. 2 Simona Halep, No. 5 Caroline Wozniacki, No. 6 Angelique Kerber and No. 7 Johanna Konta. Kerber was the defending champion.
In addition to her US Open title, Kuznetsova was the runner-up in 2007. She also was the French Open champion in 2009.
While Kuznetsova fell, CoCo Vandeweghe reached the third round for the first time in nine appearances by beating Ons Jabeur of Tunisia 7-6 (6), 6-2.
The 20th-seeded American had been 0-4 in second-round matches at Flushing Meadows.
Vandeweghe's best Grand Slam showing was a run to the Australian Open semifinals in January. Her next opponent is No. 10 Agnieszka Radwanska, the 2012 Wimbledon runner-up.
A bit of history was made earlier Thursday as American Shelby Rogers beat Daria Gavrilova 7-6 (6), 4-6, 7-6 (5) in 3 hours, 33 minutes, setting the record for the longest women's match in Open history.
After Gavrilova's backhand sailed long on match point, the 62nd-ranked Rogers raised her arms and then put her hands to her face and broke into tears. She said after the match that it didn't feel like the longest ever at Flushing Meadows, but that now that she knows that, "I'm going to be sore."
The 20th-ranked Gavrilova, who actually outpointed Rogers 133-132, had high hopes coming into the US Open after winning the final tune-up event in New Haven, Connecticut. Rogers next faces No. 4-seeded Elina Svitolina.
Previously, the longest women's match at the tournament was in the 2015 second round when Konta downed Garbine Muguruza 7-6 (4), 6-7 (4), 6-2 in 3:23.
No. 1 Karolina Pliskova had a quicker trip to the third round by rallying to a 2-6, 6-3, 6-4 victory over American Nicole Gibbs.
Pliskova turned the match around after a slow start to avoid becoming the fifth player among the top seven seeds to be eliminated.
Svitolina advanced, with a 6-4, 6-4 victory over Evgeniya Rodina, who had routed Eugenie Bouchard in the first round.
American Jennifer Brady reached the third round of her US Open debut after routing No. 23 Barbora Strycova 6-1, 6-1.
Brady had failed to qualify the previous three years but is making the most of her first appearance in the main draw.
It's the 22-year-old Brady's second time into the third round at a Grand Slam this year. She made it to the round of 16 at the Australian Open in January.
Brady raced to a 5-0 lead in the second set but was broken while serving for the match. She promptly broke back to finish off the victory in 56 minutes.
French Open champion Jelena Ostapenko also advanced, as did Japan's Naomi Osaka, who upset Kerber in the first round.
The Associated Press contributed to this report.