Madison Keys lost the opening set but hit 55 winners to upstage Wimbledon champion and fourth seed Angelique Kerber on Thursday.
Simona Halep saw off Venus Williams – who was struggling with a knee injury – to move through to the last eight on Thursday.
Olga Danilovic became the first player born in the 21st century to win a WTA title in Moscow at Anastasia Potapova's expense.
Zheng Saisai's run to a first WTA final appeared to catch up with her, as she retired when facing defeat to Wang Qiang in Nanchang.
Top seed Julia Goerges faces a favourable last-eight fixture at the Moscow River Cup after winning on Wednesday.
Alize Cornet will meet Mandy Minella in the Ladies Championship Gstaad final on Sunday after Eugenie Bouchard's retirement.
The top seed, the defending champion and the British number one all progressed to the quarter-finals at the Nottingham Open on Thursday.
Serena Williams will undergo a scan on Tuesday and see as many specialists as she can after being struck by injury in Paris.
World number one Simona Halep has not had an easy start to the French Open but she is through to round four after beating Andrea Petkovic.
Two-time French Open champion Maria Sharapova took less than an hour to beat Karolina Pliskova in Paris.
Serena Williams did what was required with a straight-sets victory over Kristyna Pliskova in the first round of the French Open.
Latvia's fifth seed Jelena Ostapenko became only the second defending champion to lose in the first round of Roland Garros.
There was glory for Johanna Larsson, who claimed her first WTA Tour crown in three years by defeating Alison Riske at the Nuremberg Cup.
An off-colour and potentially injured Simona Halep had no answer to Elina Svitolina in the Internazionali d'Italia final.
A hip strain sustained in qualifying for the Internazionali d'Italia has ruled Monica Puig out of the French Open.
There were dramatic scenes at the Internazionali d'Italia as Karolina Pliskova repeatedly struck the umpire's chair with her racquet.
Naomi Osaka defeated Simona Halep at Indian Wells earlier this year, but she could not get close to the world number one on Wednesday.
Czech 10th seed Petra Kvitova won the Madrid Open title for the third time on Saturday with a marathon 7-6 (8/6), 4-6, 6-3 victory over Kiki Bertens of the Netherlands.
Serena Williams will not start her clay-court season in Rome after pulling out of the Internazionali BNL d'Italia.
Simona Halep responded to Caroline Wozniacki's win over Daria Gavrilova by only dropping one game against Ekaterina Makarova in Madrid.
Australian Open champion Caroline Wozniacki eased into the Madrid Open second round with victory over Daria Gavrilova.
The first clay-court outing of Serena Williams' season will not come at the Madrid Open after the 36-year-old withdrew from the event.
Coco Vandeweghe and Karolina Pliskova will battle it out for the Stuttgart Open title after winning their semi-finals in straight sets.
An abdominal injury saw world number two Caroline Wozniacki withdraw from the Istanbul Cup and sent Pauline Parmentier into the semi-finals.
Tamara Korpatsch got past top-20 opponent for the first time in her career when Kristina Mladenovic withdrew due to injury.
Julia Georges beat Daria Kasatkina in Charleston on Friday, while Garbine Muguruza made light work of her quarter-final in Monterrey.
Sloane Stephens of the United States defeated Jelena Ostapenko in straight sets on Saturday to win the WTA Miami Open final.
Jelena Ostapenko will face Sloane Stephens in the Miami Open final after overcoming Danielle Collins.
Sloane Stephens battled into the WTA Miami Open final for the first time, recovering from a set down to beat former world number one Victoria Azarenka for the second tournament in succession.
Simona Halep was made to wait before she could resume her match against Ajla Tomljanovic, but quickly wrapped up victory thereafter.
Two-time winner Serena Williams exited the Cincinnati Masters on Tuesday, as Caroline Garcia and Karolina Pliskova advanced.
Serena Williams was back on form at the Cincinnati Masters, but she came off second best in a titanic tussle with Petra Kvitova.
Rising Belarusian Aryna Sabalenka knocked out world number two Caroline Wozniacki in three sets in Montreal on Thursday.
World number one Simona Halep returned to action in Canada, but she was made to work for her win over Anastasia Pavlyuchenkova.