With a flurry of breakthroughs and upsets at the Australian Open, this week's edition of the WTA rankings had its share of notable shakeups.

Zheng Qinwen made the biggest move in the Top 20 with her runner-up performance. Zheng, 21, climbs eight places from No.15 to a career high of No.7, becoming the second Chinese player ranked inside the Top 10 following former No.2 Li Na.

Zheng's latest milestone comes exactly two years after she entered the Top 100 on Jan. 31, 2022. Last year, she was named the Most Improved Player of 2023 after winning her first two Hologic WTA Tour titles, in Palermo and Zhengzhou.

Ukrainians surge back up the rankings

The Australian Open was a banner tournament for Ukraine. The country started with a record seven women in the main draw, three of whom made the second week in another national first and two of whom delivered career-best Grand Slam showings.

Dayana Yastremska became just the fifth qualifier to reach a major semifinal and rockets up 64 places from No.93 to No.29. The 23-year-old is now eight spots off the career high of No.21 she set in January of 2020.

Twenty-one-year-old Marta Kostyuk reached her first Grand Slam quarterfinal and makes her Top 30 debut at No.28, up nine places from No.37. And although a back injury halted Elina Svitolina's run in the fourth round, the 2023 Comeback Player of the Year returns to the Top 20 for the first time since March of 2022, rising four spots from No.23 to No.19.

Mertens returns to doubles top spot

Elise Mertens' reunion with Hsieh Su-Wei immediately paid dividends. Mertens reclaimed the Australian Open doubles crown -- a title she'd previously won with Aryna Sabalenka in 2021 -- for her fourth overall Grand Slam trophy.

Mertens moves up one place to return to the No.1 spot in the doubles rankings, ending Storm Hunter's 12-week spell at the summit. This will be Mertens' eighth stint at No.1, a position she first reached in May of 2021, and she will add to her 27-week total.

Hsieh climbs four places from No.6 to No.2. The 38-year-old is also the reigning champion at Roland Garros (alongside Wang Xinyu) and Wimbledon (alongside Barbora Strycova).

Top 100 debuts for Timofeeva, Brenda Fruhvirtova

Maria Timofeeva has played only three tour-level main draws in her career, but two of them have been unusually eye-catching. Last July, the 20-year-old won Budapest as a lucky loser making her WTA debut. And this fortnight, just a month after returning from a foot injury, she made the fourth round of the Australian Open as a qualifier in her Grand Slam main-draw debut.

Timofeeva, who took out Caroline Wozniacki and Beatriz Haddad Maia along the way, moves up 70 places to No.100. She becomes the first 2003-born player to enter the Top 100.

Brenda Fruhvirtova has dominated at ITF level over the past two seasons, racking up 15 titles across 2022 and 2023. The 16-year-old Czech is now bringing her level to the main tour. Fruhvirtova qualified in Melbourne for the second year in a row, and this time she notched her first Grand Slam main-draw win to reach the second round. She becomes the second 2007-born player to break the Top 100, climbing 11 places from No.107 to No.96.

Fruhvirtova is the fourth player to make her Top 100 debut at 16 years of age or younger, joining Mirra Andreeva, Coco Gauff and Ana Konjuh. Her 18-year-old sister, Linda, fell from No.84 to No.126 this week after failing to defend her 2023 fourth-round points.

New career-high rankings for Melbourne’s breakthrough performers

Timofeeva was far from the only player breaking new ground by reaching the second week of the Australian Open for the first time.

Linda Noskova, 19, delivered the tournament’s biggest upset when she knocked off World No.1, Iga Swiatek in the third round. With a quarterfinal run, the Czech player improved her record this month to 8-2. She rises 20 spots from No.50 to No.30.

Noskova had been under rankings pressure starting the year. If she had failed to defend her 330 points from reaching the 2023 Adelaide final, which had been her biggest points haul before this year, she could have fallen to the lower end of the Top 100. But the teenager responded, emerging from January with a career-best Slam result, career-best win and career-best ranking.

Anna Kalinskaya reached her first Grand Slam quarterfinal in Melbourne, defeating Sloane Stephens along the way. The 25-year-old had previously peaked at No.51 in September of 2022 but slid out of the Top 100 last October after injury setbacks. Kalinskaya has now broken into the Top 50, climbing 37 places from No.75 to No.38.

In her tournament debut, Mirra Andreeva, 16, continued to add to her reputation by routing Ons Jabeur for her first Top 10 win en route to the fourth round. Andreeva has now made the second week of two of her first four Grand Slam events and rises 12 spots from No.47 to a career-high of No.35.

Jasmine Paolini and Magdalena Frech are also both at their highest positions yet after making their debuts in the fourth round of a major. Paolini moves up seven places from No.31 to No.24, and Frech climbs 18 places from No.69 to No.51.

Other notable rankings movements

Oceane Dodin (+20 from No.95 to No.75): The Frenchwoman had never gone beyond the second round of a major in 19 previous main-draw appearances but rode a first-round upset of Zhu Lin to the fourth round last week. A former No.46, Dodin rises to her highest ranking since October of 2017.

Wang Yafan (+16 from No.97 to No.78): Ranked No.696 as recently as last March, Wang's return to the Top 100 last year was already remarkable. Her momentum was halted by appendix surgery that forced her to miss last autumn's Chinese swing, but the 29-year-old regained it by reaching the third round of a major for the first time with wins over Sorana Cirstea and Emma Raducanu.

Maria Lourdes Carle (+14 from No.124 to No.110): The Argentinian opted out of the Australian swing but instead captured the Vero Beach ITF W75 title to rise to a new career-high, with the Top 100 in her sights.

Anastasia Zakharova (+57 from No.190 to No.133): The 22-year-old made it through Grand Slam qualifying for the first time in her eighth attempt, then went all the way to the third round. She hits a new career high.

Alina Korneeva (+38 from No.179 to No.141): Twelve months on from becoming the 2023 Australian Open junior champion, Korneeva made her Grand Slam qualifying debut and reached the second round of the main draw with an impressive three-set win against Sara Sorribes Tormo. The 16-year-old climbs to a career-high. She is the youngest player inside the Top 400.

Caroline Wozniacki (+48 from No.252 to No.204): The former Australian Open champion reached the second round this year and is nearing the Top 200 after just the fourth tournament of her comeback.

Amanda Anisimova (+228 from No.442 to No.214): Playing her second tournament following a seven-month mental health break, Anisimova upset No.13 seed Liudmila Samsonova in the first round of the Australian Open and went on to the fourth round for a third time.

Clervie Ngounoue (+88 from No.490 to No.402): The Wimbledon junior champion claimed her first professional title at the Naples ITF W35 without dropping a set two weeks ago and backed it up with a run to the Vero Beach ITF W75 to start 2024 with seven wins in a row. The 17-year-old American reaches a career high.

Maya Joint (+83 from No.565 to No.483): The 17-year-old Australian marked herself as one to watch in January. After reaching the Canberra WTA 125 quarterfinals, she reached the final round of Australian Open qualifying as a wild card, falling in three sets to eventual semifinalist Yastremska. Joint moves inside the Top 500.