Feb. 3 (UPI) -- Australian Open winner Sofia Kenin climbed to No. 7 in the Women's Tennis Association rankings Monday, while fellow American Cori "Coco" Gauff moved from No. 67 to No. 51 after she upset Naomi Osaka in Australia.
Kenin, who beat Gauff in the fourth round of the Australian Open, had been ranked No. 15 entering the tourney. Serena Williams retained her No. 9 spot, but Kenin now is the highest-ranked American player.
"It's such an honor and I love representing the U.S.," Kenin said Saturday after winning her first Grand Slam, knowing she was about to jump Williams in the rankings. "Everything is coming into place. It's a dream come true. All of the hard work is paying off."
Kenin, 21, was ranked No. 1,240 at the start of 2014. Born in Moscow, but living in Pembroke Pines, Fla., she used runs at the 2017, 2018 and 2019 U.S. Open, Wimbledon 2018 and 2019 and at the 2019 French Open to climb to No. 14 in the world at the end of 2019.
Australian Ashleigh Barty kept her No. 1 world ranking after losing in straight sets to Kenin in Wednesday's semifinal round. Kenin went on to beat Spain's Garbine Muguruza in the women's singles final Saturday in Melbourne. Barty has been the top women's player since September.
Simona Halep passed Karoline Pliskova for No. 2 in the WTA rankings. Osaka -- who ranked No. 1 in the world for several weeks in 2019 -- dropped to No. 10 from No. 4 after her loss to Gauff.
Gauff, 15, ranked No. 938 in July 2018. The Delray Beach, Fla., native climbed to No. 686 at the end of 2018. She jumped up to No. 141 in the world following her run at Wimbledon 2019, which included an upset of Venus Williams.
The teen advanced to the third round of the 2019 U.S. Open, moving up to No. 106. She ranked No. 68 at the end of 2019.
"I guess I like U.S. Open [the most], but it's hard to say because I've had such good matches at all of the Grand Slams," Gauff said after her loss to Kenin. "The Australian crowd in unbelievable, even Wimbledon is. Before going to Australia, the U.S. Open was always my favorite, but now it's close."
Kiki Bertens also moved up to No. 8 from No. 10. Muguruza moved up from to No. 16 from No. 32 following her run to the women's final. Tunisian Ons Jabeur had the biggest jump in the rankings of the top-100 players, moving up 33 spots No. 45 from No. 78 after her run to the quarterfinals in Melbourne.
The 2020 French Open is the next Grand Slam on the schedule, in late May and early June.