No.5: Angelique Kerber – Quarterfinals (2012, 2018). (Getty)

Roland Garros 2019: The 32 seeds and their best French Open performance

At the age of 30, Romania's Laura Ioana Paar is having a career-best season: on her WTA qualifying debut in Nurnberg, she saved two match points against Raluka Serban to make the main draw, where she also won a round (Nurnberger Versicherungscup)

Welcome to the Tour: Paar makes main draw debut at age of 30

Two-time Grand Slam champion Victoria Azarenka is back into the Top 50, rising seven places up to World No.44 (Jimmie48/WTA)

Rankings Rockets: Azarenka back into Top 50

World No.10 Serena Williams was an Australian Open quarterfinalist (Getty)

The WTA Top 10 and their 2019 best result: The return of Serena

Anastasia Pavlyuchenkova is the defending champion, the Russian beating Dominika Cibulkova 6-7, 7-6, 7-6 last year (tournament)

Sizzling in Strasbourg: From Rezai to Pavlyuchenkova

Johanna Larsson is the defending champion, having beaten Alison Riske 7-6(4), 6-4 in the 2018 final (Getty)

Famous five: Nurnberg champions from Halep to Larsson

Sakkari and Mladenovic hug after their quarterfinal (Jimmie48/WTA)

Rome 2019: Story of the quarterfinals as Sakkari stuns Mladenovic in dramatic clash

By contrast, Naomi Osaka posted another 6-3, 6-3 scoreline in the third round over Mihaela Buzarnescu to become the only player to win two straight-set matches on Thursday (Getty)

Rome 2019: How Super Thursday unfolded

Victoria Azarenka overturned a double-break final-set deficit to score her third Top 10 win of 2019 in the second round of Rome, saving one match point down 2-5 to oust defending champion Elina Svitolina 4-6, 6-1, 7-5 (Jimmie48/WTA)

Great escapes: Azarenka joins 2019's winners from match point down

Yulia Putintseva claimed the longest victory of 2019 to date with a 7-5 6-7(5) 7-6(2) win over wild card Anna-Lena Friedsam in the Nurnberg quarterfinals (3h21m) (Nurnberger Versicherungscup)

Marathon marvels: Putintseva wins longest match of 2019, holds two victories in the Top 10

Petra Martic returns to the Top 30 after her run to the quarterfinals in Madrid (Jimmie48/WTA)

Rankings Rockets: Martic on the move, Putintseva powers up

Kiki Bertens came into the final seeking to go one better than her finalist spot in 2018 (Getty)

Madrid 2019: Story of the Bertens-Halep final