In the last event of the season before the WTA Finals, Belarus' Azarenka was too strong with her return game for her Russian opponent, winning 53 per cent (32-of-60) of her return points while capitalising on five-of-seven break point opportunities to earn a shot at world number eight Paula Badosa.
While Azarenka has no chance of qualifying for the WTA Finals – with only the top-eight players in the rankings making it through – Belinda Bencic is one of the players who can sneak in with a great result this week.
Needing to make the semi-finals to have a chance, she got off on the right foot with a 7-5 6-7 (10-12) 6-3 win against Leylah Fernandez in her opening match.
Petra Kvitova can also qualify if she reaches the final, and she started without issue, defeating Bernarda Pera 6-3 7-5.
Ekaterina Alexandrova had an outside chance of claiming a WTA Finals spot if she won this tournament, but she was the victim of the day's biggest upset, falling 6-4 7-6 (10-8) to Camila Osorio.
At 22nd in the world, Liudmila Samsonova is the lowest-ranked player in the field with a mathematical chance at qualification, but she is a step closer after handling Kaia Kanepi 6-1 7-5.
Despite Fernandez's earlier loss, it was a strong day for the Canadians, with Bianca Andreescu proving too good in her 6-2 6-4 victory against Jil Teichmann, and Rebecca Marino also only needed two sets to defeat Ann Li 6-2 7-6 (7-2).
China's Lin Zhu came from a set behind to beat France's Alize Cornet 3-6 6-3 6-4, while Ukraine's Marta Kostyuk had a much quicker result in her 6-1 6-3 triumph over Belarus' Aliaksandra Sasnovich.
World number 34 Elise Mertens had no problems in one of the biggest mismatches of the day as she defeated world number 185 Asia Muhammad 6-3 6-2, and Sloane Stephens needed only 54 minutes to advance 6-0 6-2 past Linda Fruhvirtova.
In the last match of the night, Mexico's top chance Fernanda Contreras Gomez was eliminated by Alja Tomljanovic 6-2 6-1.
Badosa was defeated in just 78 minutes by Zheng Qinwen, with the number one seed going down 6-3 6-2.
It was 19-year-old Zheng's first completed win against a top 10 opponent in her career, and she said afterwards: "Even though the score was like this, there were a lot of emotions for me in this match and I'm very proud of myself. It's not a surprise. I always knew I had the level, I just had to make it."
Second seed Garcia hit 27 aces in her match against Zhang Shuai, the most in a single WTA-level contest since Kristyna Pliskova against Monica Puig in Luxembourg 2019 (28), but it was not enough as she lost two tie-breaks to lose 4-6 7-6 (7-5) 7-6 (7-5).
Number three seed Garbine Muguruza had more success as she beat Greek opponent Despina Papamichail 6-4 6-2, while Claire Liu also eased to a win against Elise Mertens 6-4 6-1, and will play Zheng in the quarter-finals.
Eighth seed Elena Rybakina suffered a first-round exit as she lost to Liudmila Samsonova 6-2 6-4, who will play Xinyu next.
The seeds fared better over at the Korea Open, with Emma Raducanu sealing a first-round win against Moyuka Uchijima 6-2 6-4, while Magda Linette also eased past Arianne Hartono, 6-2 7-5, though fifth-seed Varvara Gracheva was knocked out by Anna Blinkova 6-4 7-6 (7-1).
In the second round, third seed Ekaterina Alexandrova is through after beating Han Na-lae 6-1 6-3, as is Lin Zhu of China following her straightforward 6-1 6-3 victory against India's Ankita Raina.
There were also wins for Tatjana Maria against Kimberly Birrell, and 17-year-old Andorran Victoria Jimenez Kasintseva against eighth seed Rebecca Marino.
Seventh seed Kasatkina had no answers in Stuttgart as she fell to a 6-1 6-1 defeat against Badosa, who recorded the ninth top-10 victory of her career and first in exactly 12 months.
Badosa has won 29 clay-court matches in the last three seasons – only Ons Jabeur (35) and Iga Swiatek (30) have won more – but the Spaniard had to enter this tournament as a wildcard.
The 25-year-old was as high as second in the world last year but has fallen to 31st, and she outlined her goal to reach the top once more after her first-round win set up an all-Spanish meeting with Cristina Bucsa.
When asked about her ambitions to return to the world's top three, Badosa said: "That's what I'm working on every day. That's one of my goals – I want to be back on the top.
"I like to play big matches, I like to be in the last rounds of the tournaments. I still know I have that level. I still know I was that player. I still believe in myself, and I hope I'm back there very soon."
Jelena Ostapenko eased into the second round with similar dominance after downing Raducanu 6-2 6-1 in just 58 minutes, teeing up a meeting with world number four Ons Jabeur on Wednesday.
Latvian Ostapenko powered 19 forehand winners and went unbroken, acknowledging in her on-court interview that familiar aggression was key to her success in the battle of two one-time grand slam winners.
"I knew against her the main thing was to step in the court," said former French Open winner Ostapenko. "I missed some balls, but I tried to be aggressive all the time when it was possible.
"Just try to take the ball early, don't give her many chances. And finally, I'm back on clay, my favourite surface."
Barbora Krejcikova was another straight-sets winner, scoring a 6-2 6-0 triumph over Liudmila Samsonova, with the reward for the 2021 Roland Garros champion being a tricky clash against second seed and Australian Open winner Aryna Sabalenka.
There was no such ease for Anastasia Potapova in a battling 6-3 3-6 7-6 (7-4) victory over Petra Martic, the Russian's ninth third-set win in 2023 – no WTA Tour player has managed more.
Tatjana Maria overcame Ylena In-Albon 6-2 4-6 7-6 (7-4) in another enticing clash, while Beatriz Haddad Maia advanced after Martina Trevisan was forced to retire when trailing 7-5 1-1 due to a right thigh injury.
The world number nine, who is yet to drop a set this week, is into her second WTA final of 2023, having triumphed in Adelaide last month.
Haddad Maia arrived in the clash fresh from winning each of her previous six encounters with top-10 opponents, including her quarter-final victory over Wimbledon champion and Australian Open finalist Elena Rybakina.
But the Brazilian had already spent almost eight hours on court in this event prior to this contest, in which Bencic dropped just five games on the way to wracking up her 11th win of the campaign – the joint-most on the WTA Tour alongside Melbourne winner Aryna Sabalenka.
She will play number eight seed Liudmila Samsonova in Sunday's final after the Russian defeated Zheng Qinwen 6-4 1-6 6-4.
After being edged out in the first set, Zheng responded to motor through the second and seemed to have the momentum going into the third, but Samsonova showed impressive resolve to see off three break points against her, before taking her first on match point.
At the Linz Open, top seed Maria Sakkari is out after going down 3-6 6-3 6-4 to sixth seed Petra Martic in a match that lasted over two and a half hours.
The Croatian will play Anastasia Potapova in the final after the number eight seed claimed yet another three-set victory this week to see off Marketa Vondrousova 6-1 6-7 (4-7) 6-3 and secure her fifth WTA final appearance.
Second seed Bencic did not drop a single set en route to Sunday's final, but she fell behind to Samsonova and was on the brink of defeat when 6-4 down in a second-set tie-break.
The Swiss dug deep to take the game to a decider, however, and she prevailed 1-6 7-6 (10-8) 6-4 in a time of two hours and 48 minutes to win the eighth WTA title of her career.
World number nine Bencic, who was also victorious at the Adelaide International 2 in January, made a slow start against an opponent she had failed to beat in three meetings.
Samsonova broke Bencic in the second and sixth games of the opening set in a dominant start as she looked to make it 5-0 in championship matches on the WTA Tour.
Bencic improved in the second set, although a break of serve apiece meant it went the distance.
Eighth seed Samsonova looked good value to wrap up a straight-sets win when 6-4 up, only for Bencic to save both championship points, and likewise at 8-7.
Three points in a row saw the 25-year-old take the tie and level up the contest, which she went on to win with a couple of breaks in the deciding set.
The third seed is still yet to drop a set in her opening three matches, as she battled past her Ukrainian opponent 32 6-2 6-4 in 94 minutes on Court Philippe-Chatrier.
Gauff's return game proved crucial against the 30th seed, who reached the Australian Open semi-finals as a qualifier back in January.
Indeed, the 2022 finalist won five of Yastremska's nine service games - taking her tally to 15-25 for the tournament - including two during a dominant opening set.
Another three followed in the second to put her on the brink of victory at 5-2 up, though she failed to convert match point as her opponent clung on to break back.
However, it proved a false dawn for the world number 30 - appearing in round three at Roland-Garros for the first time - as Gauff saved break points on her next service game to eventually hold and progress.
Her reward is a showdown with Elisabetta Cocciaretto, who will make her maiden fourth-round appearance at a major after defeating 17th seed Liudmila Samsonova 7-6 (7-4) 6-2.
Data Debrief: Gauff matches Capriati at Roland-Garros
Gauff is only the second American in the Open Era to reach the last 16 at the French Open in four successive years before turning 21, after Jennifer Capriati (1990 to 1993).
That was also her 18th match win at Roland-Garros. Since 2000, only Iga Swiatek (21) and Ana Ivanovic (19) have registered more before the age of 21.
Her fourth-round opponent has made history, with 23-year-old Cocciaretto the youngest Italian to reach the fourth round here since Francesca Schiavone in 2001.
Unseeded 29-year-old American Rogers has knocked off top seed Maria Sakkari along with Amanda Anisimova and 2019 US Open winner Bianca Andreescu on her way to the decider.
Rogers is also yet to drop a set, maintaining that run against the higher-ranked Kudermetova for a 6-3 6-4 victory in one hour and 20 minutes.
The triumph marks Rogers' biggest final in her career and her first on tour in six years.
Rogers, who trailed 2-0 in the second set, broke Kudermetova's serve with her second match point to clinch victory.
Second seed Badosa was bundled out by Kasatkina 6-2 6-4 in 46 minutes in the other semi-final on Saturday.
Badosa did not appear 100 per cent physically throughout the match and Kasatkina capitalised to secure back-to-back finals in San Jose.
The Spaniard had three break points in the decisive game before Kasatkina converted her first match point.
Kaia Kanepi and Liudmila Samsonova both powered their way into the Citi Open final with comfortable victories on Saturday.
Sixth seed Kanepi ruthlessly swept aside Australian Daria Saville 6-3 6-1 in one hour and 13 minutes, moving her closer to her fifth career title. The 37-year-old Estonian blasted 18 winners for the match.
World number 60 Samsonova proved too good for China's Wang Xiyu, winning 6-1 6-1 in one hour and seven minutes. Samsonova's big hitting was a key feature behind her win with four aces and 17 winners.
Kasatkina, who beat Shelby Rogers in the final of the Silicon Valley Classic a couple of weeks ago, dominated Parry from the jump with her powerful serve.
Parry did not stand a chance when Kasatkina would land her first serves fair, with the Russian converting 88 per cent (15-of-17) of those opportunities in the opening frame, before winning 92 per cent (12-of-13) of her total service points in the second set.
Kasatkina, who has now collected three straight-sets wins in a row, will face Australia's Daria Saville in the final after her semi-final opponent, Marta Kostyuk, withdrew due to injury.
Meanwhile, at Tennis in the Land, Liudmila Samsonova continued her red-hot form with a 6-1 6-2 semi-final victory over Bernarda Pera to book her place in the final.
Samsonova, who is yet to drop a set at the tournament, dominated both with her serve and in her return game, winning 89 per cent (32-of-36) of her service points and 56 per cent (24-of-43) of her return points. She created nine break point opportunities, while allowing zero.
She will play Aliaksandra Sasnovich in the final after the Belarusian outlasted France's Alize Cornet 6-7 (5-7) 7-5 6-3 in a match that lasted two hours and 53 minutes.
Sasnovich shot herself in the foot early with four double faults in the opening set, but cleaned it up as the match wore on, committing just two the rest of the way.
The 18-year-old Czech was impressive against the third seed as she recorded her first win against anyone in the top 30 of the world rankings.
Fourth seed Veronika Kudermetova eased past Amanda Anisimova in just an hour and 15 minutes, winning 6-3 6-0, while Liudmila Samsonova will face second seed Aryna Sabalenka in the next round after coming from a set down to beat Zhang Shuai 5-7 6-3 6-0.
Irina-Camelia Begu and Elena Rybakina also both came from behind to secure wins, with the latter beating fifth seed Danielle Collins to set up a last-16 clash against Ukrainian Marta Kostyuk, who beat Jaimee Fourlis 6-1 3-6 6-4.
At the ASB Classic in Auckland, 42-year-old Venus Williams comfortably overcame her 21-year-old opponent Katie Volynets 7-6 (7-4) 6-2, and will play China's Zhu Lin next after she eliminated sixth seed Madison Brengle 4-6 7-6 (8-6) 6-4.
Third seed Leylah Fernandez beat Brenda Fruhvirtova 6-1 6-1 to set up a last-16 tie with Julia Grabher after she defeated Tereza Martincova in three sets.
Eighth seed Rebecca Marino is through after beating Dalma Galfi in straight sets and will now face Ysaline Bonaventure, who eventually put away Caty McNally 5-7 6-4 6-4.
Viktoria Kuzmova led fourth seed Bernarda Pera 5-4 in the opening set when rain stopped play for the day.
Having won her first match on clay for two years against Greet Minnen a day earlier, Osaka was able to force a final set against 15th seed Samsonova but ultimately fell to defeat.
Samsonova won a close encounter 6-2 4-6 7-5 to book a clash with American Madison Keys – who defeated Irina-Camelia Begu in straight sets – in the next round.
Osaka had beaten Samsonova at Indian Wells last month and came close to securing another victory as she recovered well from losing the opening set.
But the Japanese star was broken to fall 5-6 behind in the final set, and the Russian made no mistake in ruthlessly closing out the victory.
Data Debrief: Samsonova ends losing streak
This was a crucial win for Samsonova, who came into the match having lost four consecutive contests, including that Indian Wells defeat to Osaka on March 9.
Samsonova did apply plenty of pressure in the final set – forcing five break points compared to just one for Osaka – and was ultimately rewarded in the closing stages of a contest that lasted two hours and 22 minutes.
Japanese star Osaka triumphed 6-4 6-1 in only 79 minutes, swiftly booking a second-round clash against Liudmila Samsonova.
Osaka reached the last 32 at the WTA 1000 events on the hard courts of Indian Wells and Miami but had lost to Martina Trevisan at the first hurdle in the Open de Rouen on clay at WTA 250 level last week.
This was therefore a welcome return to form against Belgian qualifier Minnen and represented her first triumph on the surface since beating Anastasia Potapova at this tournament in 2022.
After an even start to the contest, the first set was level at 4-4. But Osaka then assumed full control, winning eight of nine games to race to victory.
Data Debrief: Osaka dominates on serve
Osaka was not broken at all in the match and allowed Minnen only one break-point opportunity across the whole contest.
She fired down eight aces to only three double faults, and won 13 of her 16 first-serve points in the second set.
Pegula, who is the second-highest seed remaining in the field after Iga Swiatek's withdrawal, had no issue dispatching Canada's Katherine Sebov 6-3 6-1 in just 66 minutes.
Gauff, the six seed, followed suit as she raced to a 6-4 6-3 win over Canadian Rebecca Marino in just 73 minutes.
Florida's own Danielle Collins thrilled her hometown crowd with a 7-6 (7-3) 6-2 triumph against Bulgaria's Viktoriya Tomova, and rising 22-year-old talent Clare Liu made it a perfect 4-0 sweep for the USA representatives by defeating Julia Grabher 6-4 6-3.
Last week's Indian Wells Open champion Elena Rybakina was made to work in her 7-5 4-6 6-3 win over Anna Kalinskaya, while an even more gruelling effort was required in Paula Badosa's two-hour-and-52-minute 7-6 (7-2) 4-6 6-2 result against Laura Siegemund.
The top seed to fall on Thursday was eighth seed Daria Kasatkina, as she won the first set before going down 4-6 6-2 6-2 against Elise Mertens.
Liudmila Samsonova, the 12th seed, made light work of Viktorija Golubic in a 6-1 6-1 drubbing, and 22nd seed Jelena Ostapenko prevailed 6-3 6-4 against Mirjam Bjorklund.
Ostapenko will next play 13th seed Beatriz Haddad Maia after she won a strange back-and-forth contest 7-6 (7-4) 0-6 6-0 over Tereza Martincova.
Garcia, the world number 10, entered the contest off back-to-back losses for the first time since March, and Collins made it three in a row as she was just a little too good with both her serving and return game.
Collins won 63 per cent of her service points, with Garcia at 52 per cent, and she ended up securing five breaks in the match.
She will play Martina Trevisan in the second round after the Italian defeated Colombian qualifier Camila Osorio 6-3 6-4.
Neither player had an ace in the match, but the big differentiating factor was Trevisan's ability to win points off her second serve, converting 50 per cent of her chances while Osorio won only one of nine (11 per cent).
The only qualifier of the day to get a win was Louisa Chirico, who beat fellow American Alison Riske-Amritraj 1-6 7-5 7-6 (7-5).
Chirico, the world number 196, will be rewarded for her win with a showdown against world number four Paula Badosa.
Madison Keys had no issues dealing with Australian qualifier Ellen Perez 6-1 6-4 in just over an hour, and Coco Vandeweghe defeated Sofia Kenin 6-1 1-6 6-4.
In the last match of the night, Canada's Bianca Andreescu won a two-hour-and-40-minute battle against Russia's Liudmila Samsonova 7-6 (7-1) 4-6 6-2.
Second seed Raducanu conceded the match after 36 minutes having sustained an injury to her left side while down a break at 4-3 in the opening set.
The 19-year-old is scheduled to appear at Birmingham next week before heading to Wimbledon, where she reached the fourth round last year.
US Open champion Raducanu, who made her WTA Tour debut in Nottingham last year, is unsure if she will recover in time to feature at the All England Club.
"I think I pulled something, I am not really sure what exactly happened," Raducanu said.
"I have just come off court, an absolute freak injury. I don't know what I could have done more about it. That is it.
"I have no idea [about Wimbledon]. It could have just seized up and gone into spasm and then it is really bad for a few days. I have no idea. I cannot diagnose myself. I will get it checked out."
Raducanu was the only seed to exit the tournament, with top seed Maria Sakkari overcoming Camila Osorio 6-2 6-3 to advance to a second-round meeting with Rebecca Marino.
Beatriz Haddad Maia came from a set down to beat Wang Qiang 5-7 6-4 6-3, while Ajla Tomljanovic and Camila Giorgi had comfortable victories against Wang Xinyu and Sonay Kartal respectively.
Aryna Sabalenka cruised into the second round of the Rosmalen Grass Court Championships by defeating Kateryna Baindl 6-4 6-1.
Fifth seed Liudmila Samsonova, meanwhile, succumbed to a 6-3 6-4 loss to Ann Li in an hour and 22 minutes.
There would have been further casualties among the seeds had Tamara Zidansek, Ekaterina Alexandrova and Elise Mertens not fought from a set down to win their opening matches.
The 2021 US Open winner was featuring in her first semi-final since that fairytale triumph at Flushing Meadows, and took the opening set 6-4 after making a flying start on Saturday.
Ostapenko then fought back to level the match, with Raducanu first appearing to struggle with her movement when she was a break up in the second, forcing her to take an off-court medical timeout.
The 19-year old later retired citing a left glute injury when 3-0 down in the decider, ending her confidence-boosting run in Seoul and teeing up a final meeting between the top two seeds.
Indeed, Alexandrova enjoyed a more routine outing in her meeting with Wimbledon semi-finalist Tatjana Maria, downing the German 6-2 6-4 to advance to her second final of the year.
At the Pan Pacific Open in Tokyo, meanwhile, Chinese teenager Zheng Qinwen reached her first WTA Tour final with a hard-fought win over world number 13 Veronika Kudermetova.
Having required over three hours to seal her 5-7 6-3 7-6 (7-3) triumph, the world number 36 said: "After the match when I won the last point, the feeling was incredible.
"The opponent, she's playing unbelievable tennis. She has a really good serve and hits the ball hard, she moves well. It's my first time in the final. I'm so happy."
Her compatriot Zhang Shuai was unable to replicate those exploits, however, as Liudmila Samsonova eased into her third WTA final of the year with a 7-6 (7-4) 6-2 win.
In-form Samsonova has won both of her previous final appearances this year - each of which came last month - and is 3-0 in showpiece matches for her career.
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.
Unseeded Russian Samsonova beat Estonian Kanepi 4-6 6-3 6-3 to take the title in Washington on Sunday.
It was Kanepi, the tournament's sixth seed, who struck first in a tight opening set with strong serving from both players, capitalising on the only break point opportunity in the 10th game.
While Samsonova won at least 70 per cent of her service points in each of the three sets, Kanepi's effectiveness dipped after the opener, with a 77 per cent (20-of-26) success rate in the first set, which dropped to 63 per cent (15-of-24) in the second and the third (12-of-19) to provide the Russian with an avenue back into the contest.
Kanepi led 3-2 in the second set, before Samsonova rattled off the next five games, securing a double break in the process and forcing a decider.
In a tight third frame, with Samsonova leading 4-3, she created three break point opportunities and only needed the first to grab a winning buffer, serving out the match for the title.
It is the 23-year-old's first singles title since her maiden victory at the German Open 14 months ago, and she only dropped two sets in the process while defeating fifth seed Elise Mertens, second seed Emma Raducanu, China's Wang Xiyu and Australia's Ajla Tomljanovic.
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.
World number one Swiatek landed a 21st consecutive victory as she edged out US Open winner Raducanu 6-4 6-4 in an hour and 45 minutes on the German clay.
There was plenty to admire from both players, but in the end it was another straight-sets success for Swiatek, who dropped only two games in her previous round against German Eva Lys.
It makes the 20-year-old Pole the first woman to win 28 consecutive sets on tour since Serena Williams, who did so from the 2012 US Open to the 2013 Australian Open.
Swiatek broke early in the first set to take charge, and with 19-year-old Raducanu battling a back problem the rankings leader soon got ahead in the second too.
This was Raducanu's first-ever match against a player ranked inside the WTA top 10, a peculiar statistic given she is already a grand slam champion.
Swiatek, like her opponent, knows how it feels to win a grand slam as a teenage surprise package, having triumphed as a 19-year-old at the 2020 French Open when ranked only 54th in the world.
At 4-3 in the second set of this contest, Swiatek saved two break points with clinical forehand winners out of the reach of Raducanu, shouting out in satisfaction moments later as she held serve to move a game away.
Raducanu had two more break chances in Swiatek's next service game but again could not convert as her opponent sealed victory.
Swiatek said: "I'm pretty happy that today's match was longer. Not for now, but for the future it's going to give me a lot of experience.
"Right now I want to play really aggressively, and I think this game style is going to fit the surface, and it fit the hardcourts as well."
She will face unseeded Liudmila Samsonova next after the Russian, playing as a neutral, beat Laura Siegemund 7-5 6-3.
The other semi-final in Stuttgart will see second seed Paula Badosa take on third seed Aryna Sabalenka.
Badosa was a 7-6 (11-9) 1-6 6-3 winner against Ons Jabeur, while Sabalenka fended off Anett Kontaveit 6-4 3-6 6-1.
At the Istanbul Cup, Friday saw quarter-final wins for Veronika Kudermetova and Anastasia Potapova, along with Sorana Cirstea and Yulia Putintseva.
Those results set up a semi-final on Saturday between second seed Cirstea and third seed Kudermetova, with Putintseva and Potapova also facing off.
