Daria Kasatkina

In a close contest, Belarus' Sasnovich took advantage in the big moments, winning five of her 10 break point opportunities, while Sorribes Tormo could only convert two-of-nine.

While seventh seed Sasnovich was the highest-seeded winner on the day, fifth seed Irina-Camelia Begu fell victim to a shock 6-3 6-2 upset from world number 415 Sofia Kenin.

Kenin, a wildcard, now advances to the quarter-finals after winning two matches in a row for the first time since January, and prior to this week she had lost her previous nine matches.

Alize Cornet will likely meet second seed Martina Trevisan in the quarter-final after a strong 6-3 7-6 (7-1) triumph against Denmark's rising 19-year-old talent Clara Tauson.

Liudmila Samsonova needed only 59 minutes to breeze past Iryna Shymanovich 6-1 6-0, and it was similarly smooth sailing for Magda Linette as she defeated Sorana Cirstea 6-4 6-2.

Meanwhile, at the Granby Championships in Canada, only one match was able to finish before the rain halted the rest of the day's play.

Spain's Nuria Parrizas-Diaz was too much for England's Harriet Dart, winning 6-2 6-4, while top seed Daria Kasatkina will just need to add the finishing touches when she resumes her match against Magdalena Frech, leading 6-3 5-0.

The three-time grand slam winner conceded the first break of the match three games in, but she responded brilliantly to that setback to wrap up a 6-3 6-2 win within 76 minutes.

Swiatek did not face a second break point in the match as she rediscovered her composure, continuing her French Open preparations as a barrage of big winners proved too much for Pera.

Speaking on court after her win, Swiatek said: "I wouldn't say it was easy. Every match is tricky here. 

"I'm happy that I'm getting into my rhythm. Playing against a lefty is never easy, but I'm pretty happy with that. I was disciplined and focused."

It was a day of few shocks in the Spanish capital, as third seed Jessica Pegula saw off a spirited challenge from Marie Bouzkova to emerge with a 6-4 7-6 (7-2) win.

Pegula will face Italy's Martina Trevisan for a quarter-final spot after she claimed a straight-sets win over another American player in Alycia Parks.

Meanwhile, Russian duo Veronika Kudermetova and Daria Kasatkina will meet in the next round after victories against Anastasia Potapova and Lesia Tsurenko respectively. 

Swiatek needed just an hour and 23 minutes to see off Kasatkina 6-2 6-3 in Fort Worth, Texas.

The world number one was in command throughout, her movement and intensity too much for Kasatkina in the Tracey Austin Group encounter.

Swiatek saved all three of the break points she faced and converted four of the seven chances she created for herself.

She sent down 23 winners, her highest tally in a single WTA Finals match, to complete her fifth win over Kasatkina this season.

The Pole is the first player to win five or more matches against the same opponent in a single season since Petra Kvitova against Lucie Safarova in 2014.

With her 46th such win of the year (excluding Billie Jean King Cup matches), she is the first player to win 46-plus WTA main draw matches in straight sets in a season since Serena Williams (66) and Agnieszka Radwanska (46) in 2013.

BREAK POINTS WON

Swiatek - 3/7

Kasatkina - 0/3

WINNERS/UNFORCED ERRORS

Swiatek - 23/18

Kasatkina - 4/9

ACES/DOUBLE FAULTS

Swiatek - 1/3

Kasatkina - 1/1

Swiatek, who became the first female player to win 25 consecutive matches since Serena Williams in 2015, will face Bianca Andreescu in the last eight after she eased past Petra Martic 6-4 6-4.

"I didn't start well, and everybody could see that," Swiatek told reporters. "I'm really happy with the way I reacted and how I improved in the first set.

"Also how different the second set looked to the first one because I could really reset and really change the way I played. That's the most positive thing for me."

There was a shock in the final game of the day, though, as Daria Kasatkina dumped out number two seed Paula Badosa 6-4 6-4. 

Third seed Aryna Sabalenka sealed a third straight win over Jessica Pegula, easing to a 6-1 6-4 victory, while fourth seed Maria Sakkari defeated Coco Gauff 6-4 7-5.

Seventh seed Danielle Collins was knocked out by unseeded compatriot Amanda Anisimova, the 20-year-old cruising past the Australian Open finalist 6-2 6-2.

There were also victories for Jil Teichmann, who overcame Elena Rybakina 6-7 (3-7) 6-3 7-5, and ninth seed Ons Jabeur, who beat Yulia Putintseva 6-3 6-2.

The world number one cruised to a 6-1 6-1 triumph over 2021 US Open finalist Leylah Fernandez, just three days after winning the Qatar Ladies Open in Doha.

That marked Swiatek's 41st main-draw victory in WTA 1000 events in just her 53rd outing, only Serena Williams and Maria Sharapova (52 each) have won more than 40 such matches in fewer attempts.

The 21-year-old has won her last 35 hard-court matches against opponents ranked outside the world's top 30, though Swiatek said she had to adapt against Canada's Fernandez.

"It wasn't that easy for sure. It was much tougher than the score said," said Swiatek, who will look to make the fourth round for the first time in Dubai when she faces Liudmila Samsonova.

"In the second set... I needed to go a level up. I didn't have much time to get used to the conditions, but I'm just happy I could play solid tennis."

Jessica Pegula, the third favourite at the tournament, defeated Viktoriya Tomova 6-2 5-7 6-1 to set up a third-round battle with Ana Bogdan, who overcame Shelby Rogers 7-6 (7-3) 6-3.

Fifth seed Coco Gauff coasted past Aliaksandra Sasnovich with a 6-0 6-4 victory, teeing up a meeting with Elena Rybakina, who slammed six aces in a 7-5 6-2 defeat of Marie Bouzkova.

World number two Aryna Sabalenka, who defeated Rybakina at this year's Australian Open final, made light work of lucky loser Lauren Davis in a straight-sets rout as she claimed her 12th straight win in 2023.

Dubai's defending champion Jelena Ostapenko will be the next challenge for Sabalenka after defeating 17-year-old Linda Fruhvirtova for her seventh straight win at the event.

Barbora Krejcikova saved four match points en route to a 6-4 4-6 7-5 win over seventh seed Daria Kasatkina and will meet Karolina Pliskova next after she downed sixth favourite Maria Sakkari in straight sets.

Belinda Bencic and Marta Kostyuk played out the match of the day as the former claimed a 6-7 (7-9) 7-6 (7-5) 6-4 triumph, with that clash taking three hours and 27 minutes – the second-longest on the WTA Tour this year.

Kasatkina was blown away in just 78 minutes by Zheng, who only dropped three games in her 6-1 6-2 upset of the world number eight.

Zheng, who defeated world number 12 Jelena Ostapenko on Wednesday, executed her serve-and-volley approach expertly throughout, with the 20-year-old claiming the third top-10 victory of her career to reach her third tour-level semi-final.

Another Russian player stands between Zheng and a place in the final after eighth seed Liudmila Samsonova dispatched compatriot Veronika Kudermetova 6-3 6-3.

Bencic found form after edging a tough first set against qualifier Shelby Rodgers, who saw her run ended by a 7-6 (7-5) 6-2 defeat.

Second seed Bencic will face Beatriz Haddad Maia in the semi-finals after the Brazilian railed to beat Elena Rybakina 3-6 6-3 6-2 less than 24 hours after beating Yulia Putintseva in a marathon three-hour encounter.

Meanwhile, top seed Maria Sakkari secured her progress to the last four at the Linz Open with a 6-3 7-6 (10-8) straight sets win over Donna Vekic.

The Greek will face off with Petra Martic next, while Anastasia Potapova faces the unseeded Marketa Vondrousova in the other semi-final.

Iga Swiatek heads the list of contenders to carry off the trophy in Fort Worth, Texas, having enjoyed a spectacular season.

Ascendant Americans Jessica Pegula and Coco Gauff will be chasing a home victory, while Tunisia's Ons Jabeur has reached finals at Wimbledon and the US Open so loves the big occasion.

Ahead of the tournament getting under way on Monday, Stats Perform has taken a look at the eight-player field.

Swiatek still the player to beat

With no past winner in the line-up, there is every reason to look to the world number one, Swiatek, as favourite.

The 21-year-old Polish player has eight titles this year, lifting trophies at Doha, Indian Wells, Miami, Stuttgart, Rome, the French Open, the US Open and San Diego.

Indeed, she is the only grand slam singles winner in the draw, with Ash Barty having retired and Elena Rybakina absent after no ranking or race points were awarded at Wimbledon, where she was a surprise champion.

Rybakina's absence calls into question the meritocracy of this year's tournament, which is intended to showcase the top performers on tour, yet there can be no doubt the season's premier performer is in the draw.

French Open and US Open winner Swiatek's remarkable run of 10 straight-sets victories in finals (dating back to the 2020 French Open) was finally ended by Barbora Krejcikova, who sprang a shock by winning in Ostrava in early October.

But by getting back to winning ways a week later in San Diego, scrapping for a three-set victory over Donna Vekic in the title match, Swiatek produced a typically impressive response, beating Qinwen Zheng, Gauff and Pegula on her way through the draw to improve to 64-8 in her win-loss record for the year.

Here is a measure of her dominance this season: Swiatek headed the 'Race to the WTA Finals' rankings with 10,335 points, with the players in second (Jabeur) to eighth place (Daria Kasatkina) having tallies ranging between 4,555 and 2,935 points.

Is Pegula the chief rival to Swiatek?

She might not have been the player that would have sprung to mind even a month ago, but Pegula's victory at the Guadalajara Open this month was an eye-opener.

Beginning by saving match points in a thrilling three-setter against Rybakina, Pegula took down grand slam winners Bianca Andreescu, Sloane Stephens and Victoria Azarenka before swatting aside Maria Sakkari in the final.

Pegula has reached quarter-finals at the Australian, French and US Opens in 2022, and she has a tour-high 39 wins in WTA 1000 events since the beginning of last year.

She is up to third in the WTA rankings, one ahead of Coco Gauff, with the United States now having two women in the top five for the first time since October 2010, when Serena Williams was number two and sister Venus sat fourth.

As Pegula said after the Guadalajara final: "I'm definitely a very ambitious person. A little bit of a perfectionist, as well. I don't think you could win if you weren't ambitious, especially at this level.

"I feel like it's going to give me more motivation going forward knowing I can win these big titles. I think it will give me a lot of confidence ending the year, going into next year."

These are spirited words. She heads into the tournament with a 0-4 record against Swiatek in 2022, however.

Who's in, who's out, what's it all about?

As well as Swiatek and Pegula, the field for the eight-day tournament includes Caroline Garcia, Aryna Sabalenka and Sakkari, who have all featured at the WTA Finals in the past.

Four players make their debuts, including Pegula, who is joined as a newcomer by Jabeur, Gauff and Daria Kasatkina.

Gauff, 18, has become the 14th player aged under 19 to reach the WTA top five since the rankings were introduced in 1975.

She would not be the youngest WTA Finals champion, were she to lift the title, as Monica Seles has a tight grip on that record, having triumphed at the age of 16 years and 11 months at the 1990 edition.

Last year's champion Garbine Muguruza is absent. The Spaniard was expected by many to push on and enjoy a stellar 2022 season, but it did not play out that way, with the former French Open and Wimbledon winner sliding to 57th in the world rankings after a dismal campaign.

It goes to show that whoever prevails in Fort Worth, we should be cautious about treating the outcome as an indication of what to expect in the new year.