Karolina Pliskova has crashed out of the Abu Dhabi Women's Tennis Open in the second round, while Coco Gauff was also eliminated.

Third seed Pliskova suffered a stunning 6-2 6-4 defeat to Anastasia Gasanova, a qualifier ranked at 292 in the world.

Pliskova fell to defeat in only 75 minutes on Saturday, the first time she had lost to an opponent outside of the top 50 in over a year.

Gasanova, 21, beat Mona Barthel in her WTA main draw debut this week and went on to save five of the six break points she faced to record an even bigger upset against Pliskova.

"It was not me on the court," a stunned Gasanova said after winning in her first match against a top-100 player, booking a last-16 clash against Sara Sorribes Tormo.

"I was so sure of myself. I'm really happy right now.

"I'm really surprised, but when I woke up today, I thought, 'Why not? Why can't I win this match?'

"Actually, I thought I would lose in qualies or something like that, but I just kept pushing myself, like, I need to win and I want to win.

"I had a [2021] goal to be top 200, actually! I don't know if I did this today, but that's my goal. 

"To play against a top-10 player is a great opportunity for me, and it's a great chance to show how I could play."

Pliskova, therefore, starts her year on a negative note, but there were no such problems for second seed Elina Svitolina, who was a 6-4 6-1 winner against Vera Zvonareva.

Last year's Australian Open finalist Garbine Muguruza cruised through with a 6-1 6-4 victory over Aliaksandra Sasnovich and sixth seed Elena Rybakina won in straight sets against Xiyu Wang.

Muguruza will face Maria Sakkari in an intriguing last-16 match next after the Greek ended the hopes of American Gauff with a comfortable 7-5 6-2 victory.

Top seed Sofia Kenin, who made two grand slam finals last year and won in Melbourne, will resume her campaign against Yulia Putintseva on Sunday.

Sofia Kenin admitted she was given a stern test by Kirsten Flipkens before the Belgian was forced to abandon their tussle at the Abu Dhabi Women's Tennis Open.

With a month to go before Kenin begins the defence of her Australian Open title, the American world number four was fighting to avoid a second-round exit to an experienced opponent.

Flipkens took the first set 7-5 and trailed 5-4 in the second, a break down, when an injury to her left ankle caused her to retire from the match.

A run of three consecutive games and 12 unanswered points from Flipkens had seen the 34-year-old former Wimbledon semi-finalist snatch the opener.

Kenin was turning the contest around in the second set and the top seed admitted she was "a little bit upset" to see Flipkens suffer when injury struck.

"We're good friends and that's not something you like to see," Kenin said, quoted on the WTA website. "I just hope [Flipkens] can have a speedy recovery and get ready for Australia.

"She played a really good match. It was the third time we’ve played each other, and it was a really solid match from both of us. This is not the way I wanted to win."

Aryna Sabalenka could be a player to fear at Melbourne Park in February, as the world number 10 made it 11 consecutive match wins by fending off Australian Ajla Tomljanovic 7-5 6-4.

Sabalenka finished off the 2020 season with titles in Ostrava and Linz so the Belarusian is looking for a hat-trick of tournament triumphs.

Tunisian Ons Jabeur scored a 5-7 6-3 6-2 victory against Kateryna Bondarenko of Ukraine to reach the last-16 stage, and she faces Sabalenka next.

Jabeur won on the only previous occasion she and Sabalenka have met, securing a three-set win in round three of the delayed 2020 French Open.

Dayana Yastremska says she is "astonished" after the world number 29 was provisionally suspended for failing an out-of-competition doping test.

The International Tennis Federation (ITF) on Thursday revealed Yastremska was charged on December 22, having tested positive for mesterolone metabolite in a sample taken on November 24.

Ukrainian Yastremska, who reached a career-high 21st in the rankings 12 months ago, says she is not guilty of any wrongdoing and will do all in her powers to clear her name.

The 20-year-old posted on Twitter: "I firmly state that I have never used any performance-enhancing drugs or any prohibited substances.

"I am astonished and under shock, particularly given that two weeks prior to this test - on 9 November 2020 - I tested negative at the WTA event in Linz. After this last tournament of the year, I stopped practising to rest prior to the start of the new season.

"Only a very low concentration of mesterolone metabolite was detected in my urine. Given that low concentration and given my negative test two weeks earlier, I have received scientific advice that the result is consistent with some form of contamination event.

"Besides, I have been informed that this substance is meant for use as medication by men and that women are advised not to use it due to the adverse effects it causes."

Yastremska said she was "resolutely determined to do everything to clear my name".

Rising star Yastremska has three WTA singles titles to her name.

Sofia Kenin and Coco Gauff both made it through to the second round of the Abu Dhabi Women's Tennis Open on a day of few shocks. 

Seven of the nine seeds in action on Thursday advanced, with only Marketa Vondrousova and Jennifer Brady falling by the wayside. 

Those upsets came despite Vondrousova and Brady each winning their opening sets - against Hsieh Su-wei and Tamara Zidansek respectively - the latter racing through 6-0 in the first before being reeled back in. 

Kenin and Gauff had no such problems, however. 

But top seed Kenin - the 2020 WTA Player of the Year - had to stay patient as she took down 789th-ranked Yang Zhaoxuan 7-6 (7-4) 6-2. 

The first set lasted more than an hour and saw Kenin face five break points, defending each of them, with another 11 Yang opportunities following in the second, although the world number four proved more clinical en route to victory. 

"It was the first match, obviously a bit of nerves, I had to find my groove," Kenin said afterwards. "Conditions weren't easy, it was quite windy.

"The first set was tough for me. I couldn't find the ball, I guess." 

Gauff was comfortable throughout, meanwhile, swatting aside Ulrikke Eikeri 6-0 6-1 to tee up a meeting with Maria Sakkari. 

Elina Svitolina, Karolina Pliskova and Aryna Sabalenka each also progressed in two sets, as did Garbine Muguruza, overcoming a potentially tricky hurdle in the form of Kristina Mladenovic. 

Muguruza was a 6-2 6-4 winner and afterwards said: "I was trying to do my game, dominating, not letting her dominate the point. 

"It's the first match of the year, it's a little bit tricky to get the feeling, but I'm happy with the win." 

Veronika Kudermetova started the new season in style by beating 10th seed Anett Kontaveit in the first round of the Abu Dhabi Women's Tennis Open on Wednesday.

Kudermetova had won her only two previous singles matches against Kontaveit and maintained that perfect record with a 7-5 6-1 victory.

The world number 46 from Russia broke four times to seal her place in the second round, with Kontaveit winning just 48.4 per cent of points on her first serve in a rusty beginning to the 2021 campaign.

Donna Vekic was another seed to fall at the first hurdle as Bernarda Pera consigned the Croatian to a 7-6 (12-10) 2-6 6-4 defeat at Zayed Sports City International Tennis Centre.

Kirsten Flipkens could face top seed Sofia Kenin in the second round after defeating Laura Siegemund 5-7 7-5 6-4.

Ons Jabeur is aiming to break into the top 10 this year and the 15th seed got up and running for the season by seeing off Anastasia Pavlyuchenkova 7-6 (7-3) 6-3.

Daria Kasatkina, Yulia Putintseva and Ajla Tomljanovic were among the other players who advanced to round two.