World number five Kenin landed her fifth career title and second of the season at the expense of Friedsam, whose resurgence following a series of shoulder injuries was halted as the top seed prevailed 6-2 4-6 6-4.
Kenin came through a gruelling battle in her semi-final against Alison van Uytvanck but was considerably more comfortable in the opening set here, grabbing two early breaks to open up a 5-2 lead.
It was not until game two of the second set that Friedsam got into her stride, winning a break of her own to get things back on serve but then missing an opportunity in the sixth as Kenin held her nerve to tie it up at 3-3.
Undeterred, the 26-year-old Friedsam finished the set strongly, firing three aces and winning a break point at 5-4 to tee up what might have been a tense final set had she not fallen 4-1 down in the decider.
Freidsam had no answer as Kenin grew in confidence and went a double break up behind some exquisite drop shots.
The world number 45 broke back and had some hope at 4-3 but Kenin came into the match on a six-match winning streak against German players and held firm to extend that run.
The Australian Open champion saved a match point against Romanian qualifier Jaqueline Cristian on Thursday but seemed to be finding some commanding form against Dodin as she eased into a 6-1 5-2 lead.
However, the American rather meekly allowed her opponent - ranked 130 in the world - to force a second-set tie break and then threw away a 5-1 advantage as the match went the distance.
Kenin was ultimately pleased with her performance, though, after coming through 6-1 6-7 (5-7) 6-2 following over two hours on court.
"It was still not perfect today, but I definitely feel like I found my rhythm," she said. "I was playing well, dictating well.
"It was a bit of a strange match. I was up, and somehow managed to not close it out there, but overall, I think it was a good match. I played some good tennis, some good points, and I'm happy with the way that I found my rhythm after yesterday."
Kenin will face fifth seed Alison Van Uytvanck in the last four, the Belgian having dispatched Caroline Garcia in an impressive 6-2 6-2 victory.
The second semi-final will feature Russian Daria Kasatkina, who battled past Camila Giorgi in three sets, against German Anna-Lena Friedsam, who knocked out eighth seed Viktoria Kuzmova.
Sixth seed Kudermetova showed great defiance to defeat American Collins 4-6 7-6 (7-5) 6-1 on Thursday.
Kudermetova fended off five match points when serving to stay in the tournament at 6-5 down in the second set and duly forced a tie-break.
Collins, runner-up to Ash Barty in the Australian Open final last year, took a 3-0 lead in the breaker, but back came her Russian opponent to level the match.
The world number nine dominated the deciding set to seal a meeting with Bencic in the last four.
Eighth seed Bencic got the better of WTA Finals champion Garcia 6-2 3-6 6-4.
Garcia broke straight back after going 3-1 down in the final set, but Bencic broke for the fourth time in the match to go through.
Paula Badosa and Daria Kasatkina will contest the other semi-final after beating Beatriz Haddad Maia and Petra Kvitova respectively.
Elisabetta Cocciaretto saved two match points as she came from a set down to beat Bernarda Pera 5-7 7-6 (10-8) 6-4 in the quarter-finals of the Hobart International.
The 21-year-old Italian will now face 2020 Australian Open champion Sofia Kenin, who also stormed back to defeat Anhelina Kalinina 4-6 6-3 6-1.
Lauren Davis and Anna Blinkova will do battle in the other semi-final following wins over Wang Xinyu and Yulia Putintseva respectively.
That is according to renowned coach Rick Macci, who was taken aback by Kenin's skill and mentality when the American sensation had her first lesson with him at the age of five.
Macci, who has also coached the likes of Serena and Venus Williams, Andy Roddick, Maria Sharapova and Jennifer Capriati, knew Kenin was destined for greatness as he continued to nurture her talents until she was 12.
So there were no eyebrows raised from the Ohio native when the 21-year-old beat Garbine Muguruza to claim her maiden major title at Melbourne Park last Saturday, and he is in no doubt it will prove the first of many for the world number seven.
Macci told Omnisport: "I'd say by summer she'll be on top of the rankings, it's right around the corner.
"She'll be in the top five or 10 for the next 10 years, she's not going anywhere because when you show up to play, she's always going to be there.
"People don't understand what they are looking at, I can see her winning double figures grand slams, she might get 15 before she's done.
"She's the real deal, this is [Martina] Hingis, [Simona] Halep but with a tremendous mental strength that doesn't blink. She expected to win the final [against Muguruza], her father [and coach, Alex] did and I did."
Macci says there is no chance the Russia-born prodigy will become too embraced in off-court distractions with her new-found name.
He said: "That will never happen, this is a different animal. She is no one-hit wonder, there is so much stability, structure and focus inside this girl.
"She was at the Rick Macci Tennis Academy in Boca Raton [Florida] before they went to Australia getting a massage. I said, 'So what's the game plan?'. She looked at me and said, 'To be number one in the world'.
"It was not in an arrogant way, but in a matter of fact. You can say that, but she has the goods to back it up.
"She's shown you don't have to be six feet tall, you don't need a huge serve or to have tremendous power. If you understand the geometry of the court, you take the ball early and it's a game of inches from one ear to the other.
"This girl, her mental strength is unsurpassed and she's a great role model."
The then-21-year-old American had never previously played beyond the fourth round of a grand slam and became the youngest winner of the title since Maria Sharapova in 2008.
She also followed in the footsteps of Naomi Osaka, Ashleigh Barty and Bianca Andreescu, who all won their first slam finals in brilliant fashion in the previous 18 months.
Kenin’s emotions showed at various points during the deciding set and she dropped her racket and covered her face with her hands in disbelief when Muguruza’s second serve landed long on match point.
“These past two weeks, there have been a lot of emotions,” she said post-match.
“You guys could see after the match how much it all meant to me.
“This is such an honour. I’m so proud of myself, my dad, my team, everyone that has been around me. We’ve all worked hard. We’ve been through tough times. We did it. We fought. I’m just on cloud nine.”
Kenin followed up her Australian Open victory by reaching the final of the French Open later that year in October, but was beaten by Iga Swiatek.
Jabeur, a finalist at both Wimbledon and the US Open this past season, received a bye through to the second round thanks to her status as the second seed, and she had to save three break points in the opening game of the match against Tsurenko.
After repelling the early push, Jabeur rattled off the first five games to take a commanding lead, and she secured another break to begin the second frame.
Meanwhile, with half of the field still completing their first-round matchups, 12th seed Paula Badosa proved too strong for Egypt's Mayar Sherif in a comfortable 6-3 6-1 victory.
Spain's Badosa will play Canada's Leylah Fernandez in the second round after the promising 20-year-old took just 72 minutes to dispatch Russia's Evgeniya Rodina 6-3 6-2.
Rodina was the only loss from the four Russians in action on Tuesday, with Anna Kalinskaya defeating Alize Cornet 7-6 (7-4) 4-6 6-2, 19-year-old Diana Shnaider eliminating Alycia Parks 6-4 6-3, and Varvara Gracheva prevailing 7-6 (7-3) 6-2 against Anna-Lena Friedsam.
Bernarda Pera advanced past Clare Liu 6-4 6-7 (1-7) 6-3 in one of the all-American showdowns, while ninth seed Madison Keys beat Emma Navarro 6-4 6-3 and Shelby Rogers took out Danielle Collins 6-7 (2-7) 6-4 6-1 in the others.
Sofia Kenin, the 2020 Australian Open champion, handled the challenge of Aliaksandra Sasnovich 6-1 6-7 (5-7) 6-1, and two-time Australian Open champion Victoria Azarenka came back to defeat Sloane Stephens 3-6 6-3 6-2.
Australian Open champion and second seed Osaka benefited from a walkover after qualifier Nina Stojanovic withdrew ahead of Sunday's clash due to a right thigh injury.
Elise Mertens will face Osaka following the 16th seed's 6-2 0-6 6-2 win against Anett Kontaveit.
Two-time grand slam winner Muguruza rallied past Russian wildcard Anna Kalinskaya at the WTA Premier event.
However, fourth seed Kenin was sent packing as sixth seed Pliskova was tamed by nemesis Jessica Pegula in Miami.
MUGURUZA STAYS HOT
Spanish star Muguruza dug deep to earn her tour-leading 20th win of the season.
Former world number one Muguruza – the 12th seed – prevailed 4-6 6-3 6-4 against Kalinskaya, having trailed 3-0 in the final set.
"I brought my fighting spirit and I could match the level of fighting against Anna, and very happy to go through these tough matches," Muguruza said following two hours, 41 minutes on court.
"Doesn't matter if you play pretty or you play ugly, but you stay strong and you go through these rounds. That gives me an opportunity to feel better and to have another chance."
Muguruza – who has the most final appearances this season with three, having won the Dubai Tennis Championships and finished runner-up at the Qatar Open and Yarra Valley Classic – will next face eighth seed Bianca Andreescu.
Former US Open champion Andreescu overcame fellow seed Amanda Anisimova 7-6 (7-4) 6-7 (2-7) 6-4.
KENIN'S WOES CONTINUE
It has been a rough 2021 for American star Kenin.
Stunned in the second round of the Australian Open – in her title defence – Kenin then crashed out of the Phillip Island Trophy at the first hurdle.
Kenin rallied to beat Andrea Petkovic first-up in Miami, but the 22-year-old was beaten 6-4 4-6 6-4 by 27th seed Ons Jabeur.
Jabeur and Sara Sorribes Tormo – who shocked 21st seed Elena Rybakina 6-1 3-6 6-2 – will meet for a spot in the quarter-finals.
PLISKOVA FALLS TO PEGULA… AGAIN
For the third time this past month, 2019 Miami Open runner-up Pliskova went down 6-1 4-6 6-4 to 29th seed Pegula.
Australian Open quarter-finalist Pegula conquered Pliskova in Doha and Dubai before repeating the feat in Miami on Sunday.
"I played her a lot the last three weeks, three tournaments," Pegula said. "I kind of expected her to play well there. Even when I was up I still felt like she could easily come back just because she plays so aggressive and she serves well."
After reeling off the final four games, Pegula set up a last-16 showdown with 23rd seed Maria Sakkari, who dismantled qualifier Liudmila Samsonova 6-0 6-1.
The American world number three triumphed 6-2 6-0 in 65 minutes, winning the second set to love in 27 minutes.
Blinkova, who is ranked 63rd in the world, was no match for Pegula, who won 71 per cent on first serve and 65 per cent on her second. Pegula also generated 10 break points, winning 71 per cent on the Russian's second serve.
The American will take on Romanian 15th seed Irina-Camelia Begu in the round of 16, after she toppled resurgent 2020 Australian Open winner Sofia Kenin 6-1 6-4.
Defending champion and fourth seed Belinda Bencic triumphed in the evening session, breezing past Canada's Katherine Sebov 6-0 6-3 in 62 minutes.
Bencic will meet Shelby Rogers in the third round with the American edging countrywoman Caty McNally 6-7 (4-7) 7-5 6-1.
Ninth seed Madison Keys beat Hailey Baptiste 6-1 6-2, setting up a third-round clash with eighth seed Magda Linette who got past Varvara Gracheva 6-7 (3-7) 7-5 6-4.
Third seed Daria Kasatkina defeated Madison Brengle 6-2 6-1, progressing to face 38th ranked American Bernarda Para who beat Cristina Bucsa 6-3 6-4.
Spaniard Paula Badosa won 7-5 7-6 (8-6) over 2021 US Open runner-up Leylah Fernandez and will face Diana Shnaider who upset fifth seed Veronika Kudermetova 6-4 6-3.
Eugenie Bouchard's campaign at the Copa Colsanitas was halted in the second round with a 6-0 6-7 (7-9) 6-4 loss to fourth seed Kamilla Rakhimova.
The Briton, who won the US Open in 2021, went down 6-3 3-6 6-2 in a genuine tug-of-war against the 31st-ranked Canadian.
Andreescu sent down seven aces for the match, including four in the first set along with 12 winners as she claimed an early lead.
Raducanu responded with greater aggression, securing the crucial break in the eighth game, before serving out to level the contest.
But Andreescu showed composure and quality in the big points in the final set, winning the final four games to round out the victory, sealing a second-round clash with seventh seed Maria Sakkari.
Andreescu finished with 32 winners compared to Raducanu's 20, while the Briton committed 40 unforced errors.
World number 42 Shelby Rogers edged out USA compatriot Sloane Stephens in just under two hours, winning 6-4 3-6 6-2. Rogers will take on second seed Aryna Sabalenka, who is arguably the tournament favourite after top seed Iga Swiatek's withdrawal, in the next round.
Rogers was one of five Americans to progress, including 2020 Australian Open champion Sofia Kenin who defeated Australia's Storm Hunter 6-0 7-6 (7-5).
World number 35 Amanda Anisimova retired down 7-6 (7-5) 5-2 to countrywoman Madison Brengle.
Leylah Fernandez, the player whom Raducanu beat in the 2021 US Open final, advanced into the second round with a 6-4 6-3 victory over Lesia Tsurenko in 88 minutes.
Raducanu dished out a bagel to qualifier Viktoria Kuzmova in the first set of the round of 16 match in Auckland on Thursday, but the 2021 US Open champion was unable to continue after losing the second set 7-5.
The 20-year-old Brit ended a disappointing 2022 season early due to a wrist injury and suffered another blow ahead of the first major of this year, leaving the court in tears.
Gauff will be eyeing her maiden grand slam title in 2023 and she impressively dispatched fellow American Kenin 6-4 6-4 in the second round in the capital of New Zealand.
Top seed Gauff and her compatriot were forced to play indoors due to the rain and it was the 18-year-old who prevailed, breaking three times and saving six of the break points she faced.
The teenager will face Zhu Lin of China for a place in the semi-finals after she beat Venus Williams 3-6 6-2 7-5.
Leylah Fernandez inflicted a crushing 6-0 6-1 defeat on Julia Grabher after losing only two games in her first-round win over Brenda Fruhvirtova and the Canadian will now face Ysaline Bonaventure, who defeated Rebecca Marino in three sets.
Top seed Ons Jabeur made a winning start to the season at the Adelaide International, seeing off Sorana Cirstea 7-6 (7-3) 6-1 to set up a meeting with Marta Kostyuk
Irina-Camelia Begu claimed the scalp of Jelena Ostapenko with a 6-3 6-0 upset of the seventh seed, while Victoria Azarenka was a 6-2 7-5 winner against Zheng Qinwen and teenager Linda Noskova got past Claire Liu in straight sets.
Playing for the first time since she was knocked out of the Australian Open by Elena Rybakina in the fourth round last month, normal service was resumed by the domineering world number one in Doha.
The top seed brushed Collins aside in only 53 minutes, racing to a 6-0 6-1 victory to march into the third round.
Collins only won four points as she suffered the misery of a first-set bagel, an inspired Swiatek taking the opener in only 21 minutes.
Swiatek's run of games won was ended at nine when Collins got on the board at 3-1, but the Pole broke for a fifth time before serving it out for an emphatic victory.
The 21-year-old three-time grand slam champion, who made only six unforced errors, will do battle with Belinda Bencic for a place in the quarter-finals.
Bencic beat two-time champion Victoria Azarenka 1-6 7-6 (7-4) 6-4 to take her place in the last 16, storming back from 4-1 down in the second set when she appeared to be on her way out.
Second seed Jessica Pegula saved two match puts as she dug deep to beat Jelena Ostapenko 6-2 2-6 7-5 to set up a meeting with Beatriz Haddad Maia, who beat Daria Kasatkina in straight sets.
Fourth seed Coco Gauff got the better of Petra Kvitova 6-3 7-6 (8-6), while Veronika Kudermetova and Maria Sakkari also made it through.
Sabalenka hit 26 winners in the victory and now has 250 at WTA 1000 level for the season, representing one of only two female players with more than 200 in 2023.
The world number two, who is the top seed in the tournament after Iga Swiatek's withdrawal, has now won 19 of her past 21 matches, with her only losses in that span to Elena Rybakina and Barbora Krejcikova.
She will get the chance to avenge that loss to Krejcikova next after the Czech Republic representative knocked out hometown star Madison Keys 7-6 (7-4) 6-3.
Former French Open winner Krejcikova registered her 10th WTA 1000 level win against Keys, becoming only the second player to achieve that this season.
Former Australian Open champion Sofia Kenin fell 6-4 6-4 to Canada's Bianca Andreescu, who continued her strong run after previously knocking out seventh seed Maria Sakkari and 2021 US Open champion Emma Raducanu.
In a serve-dominated match, 2019 US Open champion Andreescu sent down seven aces, maintaining 70 per cent first serve percentage.
Ninth seed and former Olympic gold medallist Belinda Bencic was eliminated 7-6 (10-8) 6-3 by 18th seed Ekaterina Alexandrova, who will take on Andreescu in the next round.
Marketa Vondrousova won her all-Czech matchup against 17th seed Karolina Pliskova, and their compatriot Petra Kvitova enjoyed a 6-4 7-6 (7-3) triumph over recent Monterrey Open champion Donna Vekic.
Romania's Sorana Cirstea made it seven wins from her past eight matches with a 7-5 6-1 result over Karolina Muchova, having knocked off fifth seed Caroline Garcia in the second round.
Varvara Gracheva ensured a strong day for the Russians with a 6-1 6-2 demolition of Magdalena Frech in a battle of two unseeded players.
The number two seed won 7-6 (10-8) 7-6 (7-3), saving seven set points after going 5-1 down in the first set, before roaring back to take both tie-breaks.
Sabalenka will face Marketa Vondrousova in the quarter-finals, with the Czech having produced a dominant performance in a 6-0 6-4 win against Kaia Kanepi.
"When it's 1-5 down, it's like you have nothing to lose, and you just go for your shots without thinking," Sabalenka said.
"That really helped me to stay in the set, to keep fighting and to keep trying."
Fourth seed Veronika Kudermetova eased through after a 6-4 6-0 victory against Bianca Andreescu, while Marta Kostyuk also advanced with a hard-fought 6-7 (5-7) 6-2 6-3 win over Elena Rybakina.
At the ASB Classic in Auckland, second seed Sloane Stephens is out after falling to Rebeka Masarova.
Having been forced to resume on Wednesday after rain suspended play the previous day, Stephens struggled against her Spanish opponent, eventually losing 6-3 7-6 (7-5).
Fifth seed Wang Xiyu is also out after retiring from her match against Karolina Muchova, but seventh seed Danka Kovinic is through after a simple 6-1 6-4 win against Nao Hibino.
Kovinic will face Lauren Davis next after she overcame Tamara Zidansek 6-2 6-1, while fellow American Sofia Kenin will take on number one seed Coco Gauff in the last 16 after she beat Wang Xinyu in straight sets.
Two-time Wimbledon champion Kvitova, the 12th favourite in the United Arab Emirates, eased past Italy's Martina Trevisan 6-2 6-1 to make a dominant start.
World number 15 Samsonova was made to work to beat Paula Badosa, winning 6-7 (3-7) 7-6 (7-5) 6-4 to tee up a clash with Qinwen Zheng, who overcame compatriot Zhang Shuai in straight sets.
Samsonova's triumph took three hours and 22 minutes, the longest match of the WTA Tour season thus far, in a thrilling first-round encounter between two top-20 players.
"Playing against Paula is always tough," 14th seed Samsonova said in her on-court interview. "She's doing unbelievable, so I'm really proud that I stayed on the court until the end.
"I think I'm growing match after match, day by day. I know it's a long journey, and I hope to continue like that."
Barbora Krejcikova, the 2021 French Open champion, cruised into the last 32 with a comfortable 6-4 6-2 victory over Irina-Camelia Begu as she aims to go one better than her runners-up finish two years ago in Dubai.
Another routine victory saw American Madison Keys ease past Jasmine Paolini 6-1 6-1, but there was no such luck for 2020 Australian Open champion Sofia Kenin.
She was dispatched 6-1 6-1 by world number 26 Marie Bouzkova, while Amanda Anisimova claimed a 6-3 6-2 win over veteran two-time grand slam finalist Vera Zvonareva.
Viktoriya Tomova had too much for Kaia Kanepi in a 6-3 6-1 success, with her reward a second-round clash against third seed Jessica Pegula.
World number four Pegula lost to the in-form Iga Swiatek in the Qatar Ladies Open final on Saturday, and Leylah Fernandez will face the Pole next after beating Julia Grabher 6-4 6-2.
Williams needed two hours to overcome compatriot Christina McHale 3-6 6-2 6-3 amid blustery conditions, dropping four of the first five games before hitting her stride.
"I got myself in a hole and I was able to get out of it, so that was satisfying," said Williams, who will face Laura Siegemund in the quarter-finals after the experienced German similarly beat Coco Gauff in three sets.
"I just got mad, and honestly, I said that I wanted to win more than one match here in New Zealand. I thought about that and sometimes it's the craziest things that get you motivated."
Caroline Wozniacki, who is into the doubles semi-finals as Williams' partner in Auckland, came through a topsy-turvy encounter to beat Lauren Davis 6-1 4-6 6-4.
A dominant opening set from Wozniacki, where Davis was unable to hold serve, was not indicative of the absorbing back-and-forth that followed.
"I got a little lucky in the end and it could have gone both ways," the 29-year-old, who will retire after Melbourne, said.
Julia Goerges is up next for Wozniacki and enjoyed a more straightforward 6-3 6-2 win over Jil Teichmann.
World number one Ash Barty's first singles match of 2020 ended with American qualifier Jennifer Brady prevailing 6-4 7-6 (7-4) at the Brisbane International, where Osaka was facing a similar fate after dropping a tie-break in the opener of her match against Sofia Kenin.
The defending Australian Open champion stormed back to take the contest 6-7 (3-7) 6-3 6-1 and will face Kiki Bertens – a 6-3 2-6 7-5 winner over Anett Kontaveit.
Petra Kvitova made light work of Liudmila Samsonova, dropping only five games in a straight-sets victory, while number two seed Karolina Pliskova sowed more disappointment for the home crowd by beating Ajla Tomljanovic 6-4 6-7 (5-7) 6-1 to set up a quarter-final against Alison Riske.
Pliskova's twin Kristyna rounded out the quarter-final action at the Shenzhen Open with a 6-4 6-4 win against Kateryna Bondarenko.
She will face Elena Rybakina, who beat third seed Elise Mertens 6-4 4-6 6-2, while Garbine Muguruza and Ekaterina Alexandrova came through three-setters against Zarina Diyas and Wang Qiang respectively to reach the other semi-final.
Svitolina, 28, had been off the tour for a combination of injury and pregnancy, but was back in action for the first time since giving birth to her and male tennis player Gael Monfils' daughter Skai in October.
The Ukrainian, who reached both the Wimbledon and US Open semi-finals in 2019, won the first set after rallying back from 3-1 down in a tie-break
But the Kazakh world number 47 responded and prevailed 6-7 (3-7) 6-2 6-4 in two hours and 48 minutes, with Putintseva sapping her opponent's energy with frequent drop shots.
Former Australian Open champion Sofia Kenin was on track for victory in a topsy-turvy clash with Aliaksandra Sasnovich before rain intervened, forcing it to be re-scheduled for Tuesday with the American leading 6-1 6-7 (5-7) 3-0.
World number 50 Sloane Stephens fought back after an early scare to beat qualifier Louisa Chirico 3-6 6-1 6-2, while Alize Cornet breezed past Fiona Crawley 6-0 6-2.
Jil Teichman was one of three seeds to lose in the first round, going down 6-2 3-6 6-2 to 17-year-old Linda Fruhvirtova.
Ukrainian 11th seed Anhelina Kalinina lost 7-6 (8-6) 6-4 to Anna Kalinskaya, while 10th seed Zhang Shuai was beaten 6-4 1-6 6-3 by Julia Grabher.
Eugenie Bouchard returned for the first time since the 2023 Australian Open due to injury with a win over Ylena In-Albon 6-3 6-2 at the Copa Colsanitas in Bogota.
Third seed Nuria Parrizas Diaz was knocked out by Briton Francesca Jones, who is ranked 817th in the world, 7-6 (7-3) 6-1 in a major shock.
Svitolina made light work of Fiona Ferro on Wednesday, cruising to a 6-4 6-4 victory at the WTA 250 tournament.
The Ukrainian star and bronze medallist at the 2020 Olympic Games in Tokyo will face seventh seed Kristina Mladenovic in the quarters.
Marketa Vondrousova – the fifth seed, ninth seed Alize Cornet, Tereza Martincova and Rebecca Peterson also moved through from the round of 16.
At Tennis in the Land, second seed Anett Kontaveit secured a quarter-final berth by topping Caroline Garcia 6-3 6-3 in Cleveland.
Meanwhile, Williams and Kenin withdrew from next week's US Open at Flushing Meadows.
Williams – a two-time US Open champion – will not compete in New York due to a persistent leg injury, joining sister Serena in sitting out the year's final grand slam.
"It's super, super, super disappointing," Williams said in a video via her Twitter and Instagram accounts. "I'm having some issues with my leg all this summer, and just couldn't work through it.
"I tried my best here in Chicago [at the WTA 250 Chicago Women's Open], but I just was unable to figure out the equation. And there's been so many times where I've been able to figure it out, even not in the best of my health, but this time, I just couldn't make any miracles work."
Kenin – the 2020 Australian Open champion – withdrew after testing positive for coronavirus.
"Fortunately I am vaccinated and thus my symptoms have been fairly mild," Kenin tweeted. "However I have continued to test positive and thus will not be able to compete at the US Open next week."
"I plan to spend the next several weeks getting healthy and preparing to play well this fall. Thank you all for supporting me. I want to wish all the players the best of luck in New York."
The 21-year-old Pole, who won last year's Indian Wells, had match point at 6-0 5-0, before Liu rallied back on serve to avoid the ignominy of a double-bagel defeat, with Swiatek eventually winning 6-0 6-1.
Swiatek was in a dominant mood, winning 57 of 83 points for the match and converting five of nine break points generated. She dropped only 11 points in seven service games.
The three-time grand slam champion is 13-3 on the season, with all 13 wins coming in straight sets. In five of those matches, she has dropped just one game.
Former US Open winner Emma Raducanu moved into the third round with a 7-6 (7-3) 6-2 win over 20th seed and 2023 Australian Open semi-finalist Magda Linette.
Raducanu's win meant she has put together back-to-back victories for the first time since September, setting up a clash with 13th-seed Beatriz Haddad Maia after she beat Katerina Siniakova 5-7 7-6 (7-4) 6-3.
Fourth seed Ons Jabeur fought back from a set down to prevail over Magdalena Frech 4-6 6-4 6-1 in one hour and 44 minutes.
Former US Open champion Bianca Andreescu also overcame an early deficit to win 4-6 6-4 6-3 over Peyton Stearns.
Reigning Wimbledon champion Elena Rybakina got the edge in a tight two-set clash with 2020 Australian Open winner Sofia Kenin, triumphing 7-6 (8-6) 7-6 (7-5) in two hours and 10 minutes. Rybakina fought back from 4-1 down in the second frame.
Fifth seed Caroline Garcia overcame a wobble to win 6-1 6-7 (4-7) 6-4 over Hungary's Dalma Galfi, with 30th seed Leylah Fernandez her next opponent after beating Emma Navarro 6-2 6-4.
Two-time major winner and three-time US Open finalist Victoria Azarenka was the big casualty from the day's play, losing 7-6 (7-1) 6-3 to 2021 Australian Open semi-finalist Karolina Muchova.
Azarenka was pushed before the two-time Australian Open winner booked her spot in the last eight at Flushing Meadows.
Williams was also challenged before reaching the quarter-finals and her bid for a record-equalling 24th grand slam singles title remains on track.
But there was no such luck for this year's Australian Open champion as Kenin bowed out.
AZARENKA BATTLES THROUGH AS KENIN FALLS
Azarenka reached the US Open quarter-finals for the first time since 2015 after overcoming Czech 20th seed Karolina Muchova 5-7 6-1 6-4.
Muchova was on top early before Azarenka steadied to advance in two and a half hours.
The Belarusian, twice a US Open runner-up, was eventually too good for Muchova, who battled a leg injury late in the last-16 clash.
Azarenka won the Western & Southern Open ahead of the US Open, showing some good form since the WTA Tour season restarted amid the coronavirus pandemic.
She will next face Elise Mertens after the Belgian 16th seed proved far too good for Kenin – the second seed – 6-3 6-3 in just 75 minutes.
Mertens hit 19 winners and just seven unforced errors against Kenin, whose best run at her home slam came to an end.
The win saw Mertens reach the quarters for the second straight year.
SERENA SURVIVES SCARE
Williams came through a tough battle with Maria Sakkari, winning 6-3 6-7 (6-8) 6-3 after two hours, 28 minutes.
The American star looked set to endure more frustration in her quest to level Margaret Court's record when she trailed Sakkari by a break in the third set.
Sakkari came from a set down to defeat Williams at the Western & Southern Open.
However, she could not hold on to her advantage in the decisive set as Williams produced a response befitting her status as a 23-time major champion.
"Just felt like I was able to compete longer. I was a little fatigued last time and had some cramps, but I felt like Maria played a completely, I felt like she almost played better today. She's such a good competitor," Williams said.
"It was a really intense match."
PIRONKOVA'S FAIRYTALE RUN CONTINUES
Awaiting Williams in the quarter-finals is Tsvetana Pironkova, whose run continued with a 6-4 6-7 (5-7) 6-3 victory over Alize Cornet.
A former Wimbledon semi-finalist, Pironkova is back playing for the first time since 2017.
The Bulgarian has put together an impressive run in New York, where she had only reached the fourth round once previously – in 2012.
Former world number one and third seed Williams prevailed in a tricky test against Margarita Gasparyan in straight sets in New York on Thursday.
Countrywoman and second seed Kenin contained Canadian teenager Fernandez behind closed doors at Flushing Meadows.
It was not good news for 10th seed Muguruza, who was sent packing by unranked Bulgarian Tsvetana Pironkova.
SERENA WINS THROUGH
Williams continued her quest for a record-equalling 24th grand slam after defeating Russian Gasparyan 6-2 6-4 to set up a showdown with 2017 US Open winner Sloane Stephens.
The 38-year-old Williams hit 27 winners and just 16 unforced errors, an improvement on her numbers in the opening round, under the Arthur Ashe Stadium lights.
Williams, who has not won a slam since the 2017 Australian Open, will next meet Stephens after the American 26th seed eased past Olga Govortsova 6-2 6-2.
KENIN SEES OFF FERNANDEZ
Kenin advanced to the third round of her home slam for the fourth year in a row thanks to a 6-4 6-3 victory over Fernandez.
World number four Kenin did not face a break point in a contest lasting one hour, 21 minutes.
After firing 19 winners and three aces, Kenin will play Ons Jabeur – who took down Kaia Kanepi 7-6 (10-8) 6-0.
MUGURUZA STUNNED
Muguruza's US Open campaign came to an end in the second round, sensationally upstaged 7-5 6-3 by Pironkova, who is playing her first tournament since Wimbledon in 2017.
Australian Open runner-up and two-time slam champion Muguruza was serving for the first set when the Spaniard started to unravel.
Pironkova, who gave birth to a son during her time away from the WTA Tour, took control at the end of a tight first set and never looked back.
"I'm not going to hide, I didn't expect my first tournament to be so good and to play so well. It's welcome! That's why I came back, for these matches and these stages," Pironkova said after winning 93 per cent of her first serves.
AZARENKA ROLLS ON
Former world number one and two-time Australian Open champion Victoria Azarenka topped fifth seed Aryna Sabalenka 6-1 6-3.
A US Open finalist in 2012 and 2013, Azarenka is in fine form after winning the Western & Southern Open last week.
And Azarenka is now just one victory away from her first second-week appearance at Flushing Meadows in five years.
Meanwhile, seventh seed Madison Keys also progressed to the third round.
