Andrea Petkovic battled back to advance to the semi-finals at the Family Circle Cup in Charleston, South Carolina on Friday while Czech qualifier Lucie Hradecka upset yet another seed with a victory over Sara Errani.
Up next for the twice Grand Slam champion is Russia's Anastasia Pavlyuchenkova who ended Angelique Kerber's resurgence with a 6-3, 6-3 victory.
Sizzling hot Andy Murray roared into his seventh successive final with a commanding victory over Canadian Milos Raonic at the Western & Southern Open in Cincinnati on Saturday.
The Serbian second seed's match against France's Adrian Mannarino was delayed because of the epic five-setter between Gilles Muller and Rafael Nadal.
Top seeds Novak Djokovic and Serena Williams face challenging early tests at the US Open following Friday's draws for the year's last Grand Slam starting on Monday.
By losing, Ostapenko joins a ignominious group including, as well as Myskina, Steffi Graf, Jennifer Capriati, Svetlana Kuznetsova and Angelique Kerber who all lost as Grand Slam champions on the first run of their defences.
The Russian five-times Grand Slam champion struggled for rhythm initially on the low-bouncing grasscourt at the Mallorca Open but picked up the pace to beat Viktoria Kuzmova 7-6(8), 6-0.
Halep said she would not recover from a calf injury in time, Wawrinka underwent foot surgery that would rule him out of the Games
Former Australian Open champion Victoria Azarenka began her warm-up to the first Grand Slam of the year in convincing fashion with a 6-2,6-0 win over Russian Elena Vesnina in their first round match at the Brisbane International on Monday.
The 36-year-old, talked about what she has been going through since giving birth to her daughter, Alexis Olympia, who turns one this September.
Britain's Johanna Konta faces an anxious 24-hour wait before discovering whether she will make her debut at the WTA Finals in Singapore.
Petra Kvitova raced to a 6-1, 6-1 victory over Dominika Cibulkova in the Wuhan Open final on Saturday to capture her first title of the year with a ruthless display of power hitting.
Maria Sharapova's US Open preparations took a major blow with the Russian World No 2 forced to withdraw from next week's WTA event in Toronto.
In the women's draw, Halep is seeded 2nd after top-ranked Kerber
Roger Federer and Novak Djokovic will be out to complete unfinished business at Wimbledon on Thursday after both were denied a chance to savour match-point glory in their first-round matches.
Could French Open champion Jelena Ostapenko serve up another shock at Wimbledon this year? Or will world number one Angelique Kerber get her season back on track at Wimbledon?
IMAGES from the Miami Masters played in Key Biscayne, Florida on Tuesday
Garbine Muguruza made an imposing start to the WTA Finals by confidently swotting aside Czech Lucie Safarova 6-3, 7-6 (4) in their White Group opener on Monday.
Big names and young guns turn up the heat at US Open
Images from Day 7 of the 2020 US Open in New York on Sunday.
On Wednesday the 23-time Grand slam winner took to Twitter to express her anguish.
Novak Djokovic will begin his Australian Open title defence against Frenchman Jeremy Chardy, while reigning women's champion Sofia Kenin meets wild card Maddison Inglis, following the draw for the year's first Grand Slam on Friday.
Serena Williams' memory is not as powerful as her first serve these days, although with so many achievements to recall it would be churlish to hold that against the American great.
Victoria Azarenka's hopes of a remarkable comeback Australian Open victory crumbled under Angelique Kerber's winners on Wednesday but the Belarusian was pleased with solid three weeks Down Under that made her feel she had turned a corner.
The real Serena Williams finally turned up at the French Open on Saturday in pursuit of a 22nd Grand Slam singles title but it was to no avail as she lost to a tenacious opponent who beat her at her own power game.
Rafael Nadal reclaimed top spot in the men's ATP rankings on Monday
World number one Novak Djokovic is on a French Open semi-final collision course with nine-times champion Rafael Nadal after the draw was made on Friday.
World number one Serena Williams has started her clay-court season in dominant style, beating Anna-Lena Friedsam in straight sets in the second round of the Italian Open in Rome on Tuesday.
Serena Williams remains the 'queen' of women's tennis but don't be surprised if she's no longer No 1 by the end of the year, Martina Navratilova said Thursday.
Images from Day 4 of the 2024 Australian Open in Melbourne on Wednesday.
Images from Sunday's action at the Australian Open, in Melbourne.
Images from Day 5 of the 2021 US Open in New York on Friday.
Czech Karolina Pliskova rose to the top of the WTA rankings without striking a ball on Tuesday as results at Wimbledon saw her overhaul Germany's Angelique Kerber.
Novak Djokovic maintained his unbeaten record against Frenchman Gael Monfils with a 6-3, 6-2 win in the semi-finals of the Rogers Cup in Toronto on Saturday, while Japan's Kei Nishikori also reached the final after beating Swiss second seed Stan Wawrinka.
List of Wimbledon women's singles champions:
Those not familiar with seeing Swiatek close up can expect to see her sliding on Wimbledon's grass, as she does on the clay
Maria Sharapova is renowned for her sheer determination in the face of adversity but in Singapore on Saturday, the Russian was quick to cast doubt over her chances of winning the WTA Finals after an injury-ravaged second half of the season.
Penpix of the top women's contenders at the 2017 French Open:
The world number 181 is the first mother since 1980 champion Evonne Goolagong to reach the Wimbledon final.
Eight-time Wimbledon champion Roger Federer, who turns 40 this year, takes on Frenchman Adrian Mannarino in round one.