World number one Simona Halep and defending champion Caroline Garcia suffered second-round defeats while Elina Svitolina and Karolina Pliskova also made early exits at the Wuhan Open on Tuesday.
Halep received treatment on her back and left thigh before succumbing 6-0 7-5 to Dominika Cibulkova in the top seed's first match since losing to Kaia Kanepi in the opening round of the US Open.
Garcia will not be repeating her success of last year in China after Katerina Siniakova consigned the fourth seed to a 3-6 7-6 (7-5) 7-6 (7-4) defeat, the qualifier saving a match point in the second set before going on to pull off a shock.
Svitolina, the sixth seed, went down 6-4 2-6 6-1 to Aryna Sabalenka, while Pliskova and Kiki Bertens were knocked out after winning the Tokyo Open and Korea Open respectively last weekend.
Madison Keys retired from her match against Angelique Kerber at 6-0 4-1 down due to a knee injury on a day which saw Caroline Wozniacki, Petra Kvitova and Garbine Muguruza reach round three.
CIBULKOVA MAKES HAMPERED HALEP SUFFER
Halep injured her back during a training hit on Sunday and the French Open champion was clearly not fully fit as she suffered the humiliation of a first-set bagel.
Cibulkova showed no mercy on the hampered Romanian, who could only muster one winner in the opening set.
Halep appeared to benefit from a couple of medical timeouts as she fought back from 2-0 down in the second to lead 4-2, but the Slovakian cut down the unforced errors to avoid a decider, sealing victory after midnight.
Cibulkova will take on Daria Kasatkina - a winner over Halep in the second round of this tournament last year - in the third round.
BATTLING SINIAKOVA HANGS IN THERE TO TOPPLE GARCIA
Garcia, who became the first player to be crowned champion in Wuhan and Beijing back-to-back last year, paid the price for not being able to put Siniakova away in the second set.
The world number four from France had the opportunity to serve out the match, but failed to do so and squandered a 3-1 lead in the third before losing a tie-break.
"It was such a long battle, I'm very happy that I won," said Siniakova, who will now go up against Muguruza. "[Garcia and I] have already played a few times and every time it's three sets. Every time I played her it was really long and tough match, so I was expecting a tough one."
SURGING SABALENKA SEES OFF SVITOLINA
Sabalenka proved just how dangerous she can be once again by claiming the scalp of Svitolina.
The unseeded Belarusian secured a seventh top-10 win of the season after giving eventual champion Naomi Osaka a big test in the fourth round of the US Open.
"I've not been counting! [her wins over players in the top 10] It's always special to beat top players. I'm so happy with this result," said Sabalenka.
PLISKOVA AND BERTENS BROUGHT BACK DOWN TO EARTH
Pliskova was on a high after beating Osaka in her homeland to win the title in Tokyo on Sunday, but the eighth seed was stunned 6-1 3-6 6-3 by new Chinese number one Wang Qiang two days later.
Bertens wrapped up her third title of the year in Korea, but Anastasia Pavlyuchenkova saw off the world number 11 with a 6-4 6-2 success.
Both Pliskova and Bertens are battling to seal spots in the season-ending WTA Finals in Singapore.
|Gascoigne hits back over Scottish Hall of Fame snub|
|NBA 2018-19: LeBron closing in on Jordan, Curry chasing Miller and Allen|
|Ter Stegen should start ahead of Neuer for Germany – Matthaus|
|England´s Sterling impressed by Sancho´s work ethic|
|Vandoorne seals switch to Formula E|
|Halep to end 2018 as world number one|
|Sri Lanka´s Jayasuriya charged by ICC with breaching anti-corruption code|
|Vermaelen out for six weeks with hamstring injury|
|LeBron and Irving did not fall out, says ex-Cavs trainer|
|Ramsey out of Wales´ clash with Republic of Ireland|
|Bolt angry with drugs test|
|Bad luck is not a coincidence – Kimmich concerned by Germany form|
|Mahomes: Chiefs need to win like Brady and the Patriots|
|Schuster warns Real Madrid not to panic-buy striker in January|
|We´re here to win! - Paine not happy celebrating a draw|
|Injured Thauvin out of Germany clash|
|Southgate hits out at early Premier League start|
|Modric to Inter talk is ´fantasy´, says Guardiola|
|Pats hand first loss to Chiefs after wild shoot-out|
|Cowboys, Ravens dominate as Pats beat Chiefs in NFL classic|
|Brady becomes first QB to 200 regular-season wins in NFL|
|Red Sox level series against Astros|
|Mbappe leaves red-faced Dembele on his backside|
|Red Sox ace Sale admitted to hospital with stomach illness|
|From UFC to NFL? McGregor throws pass for Cowboys|
|Ancelotti praises ´dangerous´ Mbappe|
|Uncapped Papalii named in All Blacks squad|
|Kane would star in LaLiga – Ramos|
|Guardiola unsure about Man City´s Champions League chances|
|Dzeko: Premier League return? You never know|
|Gurley dominates to help Rams beat Broncos|
|Butler expected to play Timberwolves´ opener against Spurs|
|I´m no wizard – Mancini asks for patience with Italy|
|The Messi and Ronaldo era is phenomenal – Guardiola|
|Dolphins defeat Bears in OT with 47-yard field goal|
|Almirola picks up win at Talladega|
|Wigan´s Sarginson wanted Grand Final glory in memory of brother|
|McLeish: Scotland keep shooting themselves in the foot|
|Sarries´ walking wounded a concern for Jones|
|Poland 0 Italy 1: Biraghi seals last-gasp win to keep final-four hopes alive|
|Seahawks top Raiders with blowout win in London|
|In-demand Hogg hints at Glasgow exit|
|Holder calls on Windies batsmen to step up after India whitewash|
|France´s World Cup win hurt me - Koscielny retires from international football|
|Bailey performs U-turn on Jamaica call-up|
|Evans becomes Buccaneers´ all-time leading receiver|
|Overlooked Alba is one of the world´s best, says Ramos|
|Del Potro a major ATP Finals doubt due to fractured patella|
|Gomez to replace suspended Stones for England|
|Luis Enrique applauds ´adaptive´ Southgate|
|Pepperell holds off Bjork for wire-to-wire British Masters glory|
|Steelers´ Shazier returns to Bengals´ stadium for first time since injury|
|Scotland 1 Portugal 3: Santos´ side pile misery on McLeish|
|Falcons prey on Toulon, Vunipola brothers injured in Sarries win|
|N´Golo Kante is fundamental for France – Lucas Hernandez|
|Real Madrid star Bale withdraws from Wales squad|
|50 Cent to meet Khabib for Bellator talks|
|Drink-driving charge does not change who I am – Lloris|
|Pavard backs Varane to beat favourites to Ballon d´Or|
|Gareth gives players more input - Henderson explains Southgate, Klopp contrast|
|Stephens qualifies for WTA Finals as Svitolina sits out Kremlin Cup|
|Disrespectful critics are treating us like amateurs - Hummels|
|Final Proteas-Zimbabwe T20 washed out|
|Deontay Wilder apologises for punching mascot on live TV|
|Irrepressible Djokovic hunting year-end number one|
|Henry has everything to be a success at Monaco – Deschamps|
|Shastri: Shaw plays like Tendulkar, Sehwag and Lara|
|Germany lose Boateng for key France fixture|
|Giorgi eases past Alexandrova to Linz title|
|Why not? I hope so - Lukaku harbours Serie A ambition|