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.
|A-League Review: Mariners held as Bolt considers move|
|Dominant Svitolina ends Kvitova hoodoo in Singapore|
|Pereira warns Juventus to expect ´pumped up´ Manchester United|
|D´Antoni backs NBA to ´sort out´ Lakers-Rockets brawl|
|Mixed feelings for champion Marquez after Dovizioso crash|
|Bolt offered contract by Central Coast Mariners|
|Anthony accuses Rondo of spitting after Lakers-Rockets brawl|
|Martial insists he has good relationship with Mourinho|
|Bautista to replace Lorenzo at Phillip Island|
|Emery wanted Lacazette at Paris Saint-Germain|
|Wallabies centre Hodge suffers fractured ankle|
|Koepka claims top ranking with CJ Cup win|
|Dramatic Dovizioso crash gifts Marquez MotoGP title in Japan|
|LeBron´s home debut ends in defeat, Walker makes NBA history|
|Rondo, Ingram and Paul exchange punches in Lakers-Rockets clash|
|Dodgers to face Red Sox in World Series after beating Brewers|
|Valverde doesn´t care about extending Barca contract|
|Qualifying speed a ´positive surprise´ for Ferrari´s Vettel|
|I was in a different headspace – Hamilton revels in Austin pole|
|Barcelona can cope without Messi – Pique|
|Allegri: Juventus abandoned Genoa clash|
|Sale: Hospital visit was because of belly button ring|
|Valverde accepts Barcelona will miss Messi|
|No Messi or Ronaldo in El Clasico for first time since 2007|
|Barcelona have not won a Clasico without Messi since his debut|
|Ramos calls for Real Madrid unity after latest loss piles pressure on Lopetegui|
|Hamilton has title in sights after storming to Austin pole|
|Inter, El Clasico and more - the games Messi will miss with broken arm|
|End of Messi-Ronaldo duel good for LaLiga - Simeone|
|Messi out of Clasico with fractured arm|
|Awesome Ashton marks Sale bow with hat-trick|
|Klopp hopes for positive Henderson prognosis amid Liverpool injury issues|
|Benitez ´convinced´ Newcastle can survive despite seventh defeat|
|Barcelona 4 Sevilla 2: Messi injured but champions go top|
|Kovac relieved by Bayern´s timely victory|
|Strasbourg 2 Monaco 1: Sy howler and Grandsir red card cost Henry in first match|
|Leicester City defender Chilwell signs new six-year contract|
|PSG´s Tuchel hopes Verratti and Di Maria can face Napoli|
|Liverpool star Salah had no fear during scoring drought|
|Alonso´s 2019 plans not damaged by McLaren´s IndyCar decision|
|Edinburgh outclass troubled Toulon, Wasps and Bath play out thrilling draw|
|Barca concern as Messi substituted with worrying arm injury|
|Howe: South coast derby draw a fair result|
|Our heads were in Manchester – Allegri left fuming at Juventus´ loss of focus|
|Derby County 2 Sheffield United 1: Marriott blunts Blades with 77th-minute winner|
|We have so many problems – Jokanovic alarmed by Fulham defensive woes|
|Huddersfield Town 0 Liverpool 1: Salah snaps winless streak|
|Pellegrini ruing injuries after Yarmolenko hurts ankle|
|Villarreal 1 Atletico Madrid 1: Simeone´s side denied LaLiga top spot|
|Gracia: Not easy to dominate Wolves like that|
|Isner´s Finals hopes hindered by Stockholm defeat|
|Dyche incredulous at refereeing decisions in Man City thrashing|
|Juventus 1 Genoa 1: Champions´ winning run ends despite record Ronaldo goal|
|´Fantastic´ Lamela urged to find consistency by Pochettino|
|You don´t want to lose any players - Young speaks out on Wade NFL speculation|
|Championship Review: Smith gets off to a winning start, Leeds beaten|
|Guardiola hails extraordinary Fernandinho after Burnley drubbing|
|Pochettino lauds Lloris as one of world´s best after West Ham heroics|
|Paris Saint-Germain 5 Amiens 0: Ten wins in a row for PSG as Neymar rests|
|Cristiano Ronaldo nets record 400th league goal|
|Marcelo backing beleaguered Lopetegui despite Madrid slump|
|Garcia dazzles to hit the front at shortened Valderrama Masters|
|Cardiff City 4 Fulham 2: Paterson gets Bluebirds off the mark|
|Newcastle United 0 Brighton and Hove Albion 1: Benitez´s men bottom after dismal defeat|
|West Ham 0 Tottenham 1: In-form Lamela settles London derby|
|Manchester City 5 Burnley 0: De Bruyne returns in comfortable win|
|Wolves 0 Watford 2: Capoue and Pereyra turn form book on its head|
|Bournemouth 0 Southampton 0: Howe´s side stifled by Saints|
|Prove you´re crazy about Inter - Spalletti rallies players ahead of Milan derby|
|Wolfsburg 1 Bayern Munich 3: Lewandowski leads Kovac out of trouble|