World number two Iga Swiatek showed why she is next in line to occupy the top ranking as she comfortably handled the challenge of 14 seed Cori Gauff 6-3 6-1 to earn a spot in the quarter-finals at the Miami Open.

Swiatek, 20, will become the first Polish-born man or woman to earn the number one singles ranking when it is next updated on April 4, after Ash Barty's retirement, and she never gave Gauff a chance.

She won all eight of her service games in the match, and broke Gauff's serve four times in eight chances to rattle off five consecutive games to close the match.

After a walkover in her last fixture, Naomi Osaka was strong on her way to a 6-3 6-4 win against Alison Riske.

Both women produced break points throughout the match, but while Osaka saved seven out of eight, coming back to double-break after her slip-up in the second set, Riske could only save nine of 12.

In a clash between top-10 seeds, Danielle Collins was terrific in her 6-2 6-4 win against Ons Jabeur.

The match was decided by each woman's success on their second serve, as Jabeur had the better first serve, but could only win 31 per cent of her second serves (8-26), while Collins was an even 73 per cent on both her first and second attempts.

Daria Saville continued her march back up the rankings with a 5-7 6-4 7-5 win against Lucia Bronzetti, making it nine wins from her past 10 matches for the Australian ranked 249 in the world after recently returning from a long-term achilles injury.

Saville will play Switzerland's Belinda Bencic after she breezed past Belarus' Aliaksandra Sasnovich 6-2 6-3, while Petra Kvitova got the better of higher-ranked Veronika Kudermetova 7-6 (7-5) 6-4.

American Jessica Pegula was nearly flawless on her way to a 6-0 first set before Ukrainian Anhelina Kalinina retired due to injury, while world number six Paula Badosa beat wildcard Linda Fruhvirtova 6-2 6-3.

Naomi Osaka moved into the fourth round at the Miami Open without even taking the court on Saturday, getting a walkover victory as Karolina Muchova withdrew.

The former world number one claimed straights sets victories coming into Saturday and had her run eased even further, with Muchova citing abdominal injury after almost five hours on court in her opening two matches.

Muchova has been sidelined due to the injury for the last seven months, missing the US Open in 2021 as well as the Australian Open this year.

"I'm sad that I cannot put up a battle against Naomi today." Muchova tweeted. "After a long break from tennis, two tough matches in [a] row have been a lot for my body and I need longer to recover."

While Lucia Bronzetti also won in a walkover, Osaka will face Alison Riske, who defeated fellow unseeded American Ann Li 6-2 3-6 6-3.

In her third match since losing to Ash Barty in the Australian Open final, Danielle Collins defeated Vera Zvonareva 6-1 6-4 in 78 minutes.

The American world number 11 has had to deal with numerous niggling injuries this season, including a viral illness that left her with significant neck pain.

"There was obviously an emotional moment for me, the pain I'm dealing with right now with this injury," she said post-match.

"Just trying to work through that, I think is one of the hardest things we go through mentally when we're on court."

Fellow seeds Belinda Bencic and Ons Jabeur also made their way through to the fourth round, defeating Heather Watson and Kaia Kanepi respectively.

Both won with relative comfort, with Bencic winning 6-4 6-1, and Jabeur only dropping three games in the opening set to triumph 6-3 6-0.

Elina Svitolina and Simona Halep both fell in the first round of the Qatar Ladies Open, while Garbine Muguruza and Anett Kontaveit eased through on Monday.

Former world number one Halep, champion in Qatar back in 2014, was off the pace as Caroline Garcia claimed just her second win in nine meetings against the Romanian with a 6-4 6-3 triumph.

Number 10 seed Svitolina also suffered an early exit after ending up on the wrong side of an almost three-hour slog, with Tereza Martincova eventually succeeding 6-7 (2-7) 7-5 7-6 (7-5).

But fifth favourite Muguruza – a two-time finalist, including in 2021 – did not have much as trouble as she outfought Sorana Cirstea 7-6 (7-4) 6-1 in a second-round contest, with Kontaveit coasting through to round three in similar fashion with a 6-2 6-3 win over Ana Konjuh. 

Jelena Ostapenko, who is a former finalist in Doha and champion in Dubai last week, managed a sixth consecutive victory in the Middle East as she downed Oceane Dodin 6-4 6-2 to reach the second round, while 11th seed Elena Rybakina fell at the first hurdle to Jacques Cristian in a 6-4 6-3 loss.

Angelique Kerber, the 13th ranked player at the tournament, was another surprise first-round loser as she fell 4-6 6-3 6-2 to Jil Teichmann.

Cori Gauff secured her spot in the second round with a straightforward 6-2 6-3 victory over American compatriot Shelby Rogers, while 16th seed Elise Mertens battled to a 6-3 2-6 7-5 win over Jasmine Paolini.

Meanwhile, defending champion Petra Kvitova had no trouble easing past Irina-Camelia Begu 6-3 6-1, and Daria Kasatkina edged out Ajla Tomljanovic 6-4 6-7 (4-7) 6-2.

Belinda Bencic made a painfully sharp exit from the Qatar Open as she was beaten 6-4 3-6 6-3 by rising star Clara Tauson.

The Olympic champion was the highest-profile casualty on day one, losing to a player making her main-draw debut in a WTA 1000 event.

Only the second Danish player to appear in Doha, after former world number one Caroline Wozniacki, the 19-year-old Tauson came from 4-2 down to take the opening set, before Bencic levelled up.

But Tauson was not to be denied. The world number 33 gained a crucial break in game four of the decider, before winning 12 of the last 13 points on her serve to set up a second-round clash with third seed Paula Badosa.

"It was a very tough match," said Tauson, who hit seven aces. "I know Belinda is playing very well, so I had to play my best today, and I did sometimes. 

"I have my confidence, but every match is really tough at this level, so I'm doing my best."

Two-time champion Victoria Azarenka survived a scare to scrape past Kazakhstan's Yulia Putintseva 5-7 6-2 7-5.

The 12th seed, who is aiming to become the first player to lift this trophy three times, recovered from two breaks down in the decide before rescuing match point at 5-4 down and eventually scrambling over the line.

Amanda Anisimova, who defeated Bencic and Naomi Osaka at the Australian Open, built on her early-season momentum by seeing off Beatriz Haddad Maia 7-5 6-4.

Ninth seed Jessie Pegula – a quarter-finalist in the season's opening grand slam – beat doubles world number one Katerina Siniakova in straight sets, while former Australian Open champion Sofia Kenin lost in three sets to fellow American Ann Li.

Maria Sakkari is handling the pressure of playing as top seed in a WTA Tour-level tournament for the first time, as she put herself to within one win of the final at the St Petersburg Ladies Open.

The Greek world number seven saw off a stern test from Elise Mertens on Friday, winning 7-6 (9-7) 6-2 to reach the semi-finals.

Sakkari had to salvage three set points in the opener, but eventually came out on top in the tie-break at the first time of asking.

Even with a comfortable lead in the second set, she failed to take the first three match points on offer, but got the fourth over the line to progress to her first semi-final of the season.

Sakkari, 26, previously reached the St Petersburg semi-final in 2020, where she lost to Elena Rybakina.

"When you're down in the score, you try to play more aggressively and [Elise] was playing really good in the last couple of games," Sakkari explained. 

"She came up with good serves and solid shots from the baseline. I just fought hard."

Next up

Irina-Camelia Begu stands in the way of Sakkari and a place in the final. 

The unseeded Romanian overcame two-time grand slam champion Petra Kvitova in the last 16 and defeated Tereza Martincova 6-4 6-2 in her last-eight tie.

It took just 85 minutes for Begu to secure her place in a fourth semi-final of her career at WTA 500 level or higher, but the first since 2017 in Moscow.

Kontaveit continues remarkable indoor run

World number nine Anett Kontaveit will face Jelena Ostapenko in the other semi-final, after ousting Tokyo 2020 gold medallist Belinda Bencic 7-6 (9-7) 6-2.

After her defeat of Bencic, second seed Kontaveit has now won 18 successive matches at indoor tournaments. She is the first player since Justine Henin in 2010 to go on such a streak.

Last year, the Estonian won titles in Ostrava, Moscow and Cluj-Napoca, which form part of this run.

Ostapenko, meanwhile, beat Aliaksandra Sasnovich 7-6 (7-5) 4-6 6-3 to take her place in the last four. The 2017 French Open champion has only lost to top-10 players so far in 2022 (Paula Badosa and Barbora Krejcikova).

Maria Sakkari and Anett Kontaveit were among the big names to cruise through to the quarter-finals of the St Petersburg Ladies Trophy on Wednesday.

Top seed Sakkari faced Ekaterina Alexandrova in the second round and recorded a routine 6-2 6-4 triumph as she looks to bounce back from a fourth-round exit at the Australian Open. 

The Greek will next face a difficult contest with Elise Mertens, who needed three sets to see off the challenge presented by Petra Martic and seal a 6-4 3-6 6-2 success. 

Second seed Kontaveit recorded a 6-4 7-5 victory over Romania's Sorana Cirstea to set up a tantalising meeting with Belinda Bencic after the Swiss downed Kaja Juvan 6-1 7-6 (7-2). 

World number 12 Elena Rybakina, meanwhile, needed less than an hour to record a straight-sets victory over Varvara Gracheva, booking an encounter with Tereza Martincova in the round of 16. 

Seeds Anett Kontaveit, Belinda Bencic and Elise Mertens all came through their first round matches at the St Petersburg Ladies Trophy on Monday.

Eighth seed Mertens came back from a break down in the deciding set to beat Alize Cornet 3-6 6-2 6-4.

Mertens, who had not beaten Cornet since 2018, will face either Petra Martic or Kamilla Rakhimova in the next round as she bids to reach her first quarter-final of 2022.

"It was a very tight match," Mertens said. "It could go either way, it was a battle. It's always difficult against her but I just kept fighting.

"I think I raised my level a little bit in the second and third sets. I stepped more into the court, the service was a bit better and I ran better."

Second seed Kontaveit needed three sets to get past Jil Teichmann, ultimately prevailing 6-3 1-6 6-3, while number five seed Belinda Bencic squeezed past Veronika Kudermetova 6-2 4-6 7-6 (7-5).

In Monday's other game, Ekaterina Alexandrova defeated Camila Giorgi 6-2 1-6 6-2.

Daria Kasatkina reached her second semi-final in as many weeks with a straight-sets victory over Garbine Muguruza at the Sydney Tennis Classic on Wednesday.

The world number 26, who was defeated by Amanda Anisimova in the Melbourne Summer Set 2 semi-finals last week, beat second seed Muguruza 6-4 6-4.

Kasatkina held throughout the opening set, landing 67 per cent of her first serves, and saw the job through in the second despite a couple of early breaks for Muguruza.

It is the Russian's first win over a top-five opponent since beating Caroline Wozniacki at the 2018 French Open.

She will now face fifth seed Paula Badosa, who saw off Olympic gold medallist Belinda Bencic 7-6 (8-6) 3-6 6-3 in an entertaining match lasting two hours and 35 minutes.

The other semi-final in Sydney will be contested between Anett Kontaveit and Barbora Krejcikova, who advanced past Ons Jabeur and Caroline Garcia respectively.

Krejcikova proved far too strong for Garcia, prevailing 6-0 6-2 in 70 minutes, while Kontaveit was in action for just 43 minutes before being handed a walkover win in her match.

Jabeur had targeted "payback" against Kontaveit after her quarter-final opponent pipped her to the final WTA Finals spot in November, but injury cost her the chance to do so.

Having lost the first set 6-4, Jabeur – who eliminated Petra Kvitova in the previous round – felt unable to continue due to a lower back injury.

At the Adelaide International 2, three of the five Americans in action made it through to the semi-finals.

Alison Riske's clash with compatriot Madison Brengle ended early due to the latter retiring with the first set level at 3-3. Tamara Zidansek awaits Riske after beating Lauren Davis 7-6 (7-4) 7-6 (9-7).

Coco Gauff and Madison Keys will meet in the other semi-final, meanwhile, following victories over Ana Konjuh and Ludmilla Samsonova in two and three sets respectively.

Tokyo Olympics gold medalist Belinda Bencic has tested positive for COVID-19 ahead of next month's Australian Open and is experiencing "severe" symptoms.

World number 23 Bencic returned a positive test, along with Ons Jabeur, after competing at the Mubadala World Tennis Championship in Abu Dhabi.

The pair are the third and fourth players to have tested positive after travelling to the Abu Dhabi event, following 2021 US Open winner Emma Raducanu and 20-time major winner Rafael Nadal.

Bencic wrote on Twitter: "Unfortunately and even though I am fully vaccinated, I recently tested positive for Covid-19.

"I am currently isolating and taking all precautionary [measures] to get through this as best as possible as I am experiencing quite severe symptoms (fever, aches, chills)."

The Mubadala World Tennis Championship typically serves as a warm-up event prior to the Australian Open which is due to begin on January 17 in Melbourne.

World number 10 Jabeur, who defeated Bencic in Abu Dhabi, is experiencing "strong symptoms" and isolating in her native Tunisia.

World number one Ash Barty will start her 2022 season at the Adelaide International along with eight of the other current 10 top players in the world.

Barty has held top spot in the women's rankings since September 2019 and collected five titles – including Wimbledon – in the 2021 season but missed the French Open with a hip injury.

She also opted to not play in the season-ending WTA Finals in Mexico due to coronavirus-enforced quarantine concerns that could disrupt her preparation for the following campaign.

The Women's Tennis Association (WTA) confirmed on Friday that Barty would begin her 2022 season in Adelaide on January 2, along with defending champion Iga Swiatek, WTA Finals victor Garbine Muguruza and Roland Garros winner Barbora Krejcikova, as the world's elite players prepare for the Australian Open.

The entry list for the WTA 500 tournaments also includes Tokyo Olympics gold medallist Barbara Bencic, who finished runner-up to Swiatek in 2021, former world number one Karolina Pliskova and US Open runner-up Leylah Fernandez.

The field boasts 12 major trophies between them, but three grand slam winners will kick-start their seasons in Melbourne the day after.

Naomi Osaka, who is aiming to defend her title at the Australian Open, gets her preparations underway in the Melbourne Summer Set.

Two-time major winner Simona Halep and reigning US Open champion Emma Raducanu will play in the Melbourne Summer Set.

The trio are among 20 of the top 50 ranked players in the world for the two WTA 250 tournaments starting on January 3, with the entry list split between the competitions the week before matches start.

Raducanu will feature in just her eighth Tour-level event, and her fourth tournament since winning her first major, while Osaka will be appearing for the first time since an early defeat in the third round of the US Open to Fernandez.

Late stand-in Liudmila Samsonova produced a mesmerising fightback to beat Olympic champion Belinda Bencic and clinch the Billie Jean King Cup for the Russian Tennis Federation.

After Daria Kasatkina swept to a 6-2 6-4 win over Jil Teichmann to put the Russians ahead against Switzerland, Samsonova produced a high-quality performance to win 3-6 6-3 6-4 against Bencic.

It meant there was no need for a doubles decider, with the Russian squad taking the match 2-0.

Samsonova had not expected to be involved in the singles contest in Prague, but a knee problem forced Anastasia Pavlyuchenkova to pull out just minutes before Saturday's final got under way, forcing Russian captain Igor Andreev into a reshuffle.

A worthy substitute, Samsonova is ranked 40th in the world, while Bencic sits at number 17, and this win was the Russian's third victory in three meetings this year with the Tokyo 2020 gold medallist.

One of those came in the final of the Berlin grass-court tournament, and the 22-year-old was not over-awed by another big occasion this time.

Just as she did in Berlin, Samsonova lost the opening set but then dominated, and by doing so she secured a fifth Russian triumph in this team competition, previously known as the Fed Cup.

Samsonova said: "I have too many emotions now. It's unbelievable. I'm unbelievably happy. It was an incredible fight. It was a more nervous game. It was more than tennis."

Andreev spoke of the strong bond in his squad, saying: "It's an historical win for us. It's been a long time without any trophies in team tennis. I'm very proud and very happy for the girls, the way they played.

"They're amazing, they're heroes, and they achieved this because they're a team – a real team – and real friends."

Russia dominated this event from 2004 to 2008, winning four of five titles, while Switzerland had only previously been to one final, when Martina Hingis and Patty Schynder were outmatched by Arantxa Sanchez Vicario and Conchita Martinez in the 1998 showpiece.

Australia and Switzerland secured their spots in the semi-finals of the Billie Jean King Cup and will go up against each other for a place in the final.

Belarus proved no match for Australia, who got the job done across their two singles matches on the day in the Czech Republic.

Storm Sanders got the ball rolling as she comfortably saw off Yuliya Hatouka 6-3 6-3 in the first contest of the day in Group B.

Ajla Tomljanovic was made to work a little harder by Aliaksandra Sasnovich as she lost the first set but eventually rallied to overcome her opponent 4-6 6-2 6-3.

It meant the two countries' doubles meeting was a dead rubber – Belarus at least took the opportunity to avoid a 3-0 annihilation as Sasnovich teamed up with Lidziya Marozava in the 6-4 6-4 defeat of Olivia Gadecki and Ellen Perez.

In Group D, Switzerland and the Czech Republic claimed one victory apiece in the singles – Marketa Vondrousova had too much for Viktorija Golubic in a 6-4 6-2 success that gave the Czechs the upper hand.

But Belinda Bencic levelled things up despite the unenviable task of facing world number three Barbora Krejcikova, emerging with a 7-6 (7-2) 6-4 success.

Bencic was then involved in the doubles decider as well, getting the better of Lucie Hradecka and Katerina Siniakova with Jil Belen Teichmann, their 6-3 6-3 win sealing the semis spot for the Swiss.

The Russian Tennis Federation – who eliminated defending champions France on Wednesday – and the United States are due to contest the other semi-final.

Belinda Bencic fought back to beat Angelique Kerber in a blockbuster showdown and help Switzerland eliminate Germany on day two of the Billie Jean King Cup in Prague.

Germany lost to hosts Czech Republic on the opening day and were brushed aside 3-0 by Switzerland on Tuesday, with world number nine Kerber losing 5-7 6-2 6-2 to Bencic.

Kerber was carrying an injury and was outlasted by the Olympic gold medallist, with that triumph coming after Viktorija Golubic defeated Andrea Petkovic 6-4 7-5.

Golubic and Jil Teichmann added further gloss to the scoreline by overcoming Anna-Lena Friedsam and Nastasja Mariana Schunk in the doubles.

Switzerland will now meet the Czech Republic in a winners-takes-all contest to determine who finishes top of Group D.

The upset of the day came in Group B as Australia beat Belgium 2-1, with Daria Gavrilova kicking things off by beating Greet Minnen 6-4 1-6 6-4.

Storm Sanders then battled back to beat Elise Mertens 4-6 7-6 (7-5) 6-0, rendering Mertens and Minnen's doubles win nothing more than a consolation. 

In Group A, Russia cruised to a 3-0 win over Canada.

Daria Kasatkina beat Carol Zhao 6-3 6-1 and Anastasia Pavlyuchenkova was too strong for Rebecca Marino as she prevailed in three sets.

Slovakia top Group C, meanwhile, after beating the United States 2-1. Shelby Rogers fell 6-4 6-4 to Viktoria Kuzmova before Danielle Collins levelled with a 6-3 6-2 win against Anna Karolina Schmiedlova.

That set up a decider in the doubles, which went the distance as the Slovakian pair of Kuzmova and Tereza Mihalikova prevailed 6-2 6-7 (5-7) 12-10 in a thriller with Caroline Dolehide and CoCo Vandeweghe.

Anett Kontaveit beat Olympic champion Belinda Bencic and will face home favourite Petra Kvitova for a place in the Ostrava Open final.

Estonian Kontaveit, ranked 30th in the world, claimed her fourth top-20 win of the season as she prevailed 6-4 6-3 on Friday.

Kontaveit also defeated Bencic in the 2020 Australian Open, meaning she is 2-0 in their head-to-head rivalry.

Czech left-hander Kvitova awaits in the last four, after the second seed defeated Bencic's Swiss compatriot Jil Teichmann 6-4 6-4.

Teichmann beat Kvitova in their only previous meeting, but the world number 10 had too much on this occasion, along with the backing of the crowd to boot as she chases a 29th singles title of her career.

The other semi-final will see top seed Iga Swiatek face Maria Sakkari.

Last year's French Open winner Swiatek reached her first semi-final since May – when she landed the prestigious title in Rome – by overcoming Elena Rybakina 7-6 (7-5) 6-2.

Sakkari, meanwhile, ended Tereza Martincova's hopes in straight sets.

Greek star Sakkari ended Swiatek's reign as Roland Garros champion in June, beating the Polish 20-year-old in the quarter-finals in Paris.

Olympic gold medallist Belinda Bencic eased to a straight-sets win over Sara Sorribes Tormo to maintain her good form and book a place in the Ostrava Open quarter-finals.

Third seed Bencic needed just 88 minutes to see off her 36th-ranked opponent as she made it 15 victories from her past 18 matches.

Czech wildcard Tereza Martincova is also through to the last eight on home soil after battling past French Open finalist Anastasia Pavlyuchenkova 7-6 (7-5) 7-6 (8-6).

Martincova is into her fifth quarter-final of the season and will take on number four seed Maria Sakkari, who saw off Jelena Ostapenko 6-4 6-2 earlier on Thursday.

Also through to round three is Elena Rybakina following a hard-fought 6-3 2-6 6-1 win over qualifier Magda Linette, while Jil Teichmann – who shocked former world number one Angelique Kerber in the previous round – advanced in three sets against Alison Riske.

She will face Petra Kvitova for a place in the semi-finals.