Ash Barty stunned the sporting world on Wednesday by announcing her retirement from tennis, bowing out as the top-ranked player in the women's game.

The popular 25-year-old has not featured since winning her home grand slam at the Australian Open in January, becoming the first female Aussie singles champion of the tournament since Chris O'Neil in 1978.

Announcing the news on her Instagram page, Barty cited achieving a lifelong goal of winning Wimbledon last year as a primary factor behind her decision as well as being "spent physically".

But Barty is by no means the first sporting hero to retire at the top of their game. Below we take a look at some other examples of those who have exited as champions.

ALAIN PROST

The 1993 Formula One season was largely dominated by one man – Williams driver Alain Prost. The Frenchman had to battle hard with the iconic Ayrton Senna at the start of the campaign, with them each taking three wins from the first six races of the season. However, a run of four straight victories for Prost were followed by a string of retirements for Senna, ensuring a fourth world title that provided the ideal ending to a glittering career.

ALEX FERGUSON

One of the most successful managers in world football, Alex Ferguson began a 27-year stint at Manchester United after an excellent spell at Aberdeen. The Scot won 28 major trophies at Old Trafford, including 13 Premier League titles, five FA Cups and two Champions Leagues. His final trophy came with top-flight glory in 2012-13, and 17 days later he brought the curtain down.

PEYTON MANNING

Considered one of the greatest quarterbacks of all time, Peyton Manning won his first Super Bowl with the Indianapolis Colts in 2007 and, after an injury-blighted season that raised doubts about his ability aged 39, he added a second with the Denver Broncos in 2016, bowing out on the ultimate high.

RICHIE MCCAW, DAN CARTER

New Zealand became the first nation to successfully defend the Rugby World Cup trophy by beating Australia 34-17 in the final at Twickenham in 2015, adding to their success on home soil four years prior. It proved the end of the line for captain Richie McCaw, who was at the time the most capped player in rugby union with 148 appearances for the All Blacks, as well as mercurial fly-half Dan Carter. Ma'a Nonu, Conrad Smith and Kevin Mealamu were also among an influential contingent that opted to end their international careers.

PETE SAMPRAS

In defeating Andre Agassi in the final of the 2002 US Open, the same opponent he overcame to win his first grand slam 12 years prior, Pete Sampras secured his place among the greats in men's tennis. It was a then-record 14th major singles title for a male player for the American, a milestone that has since been surpassed by Roger Federer, Rafael Nadal and Novak Djokovic, but he did not compete again and announced his retirement almost one year later.

PHILIPP LAHM, MIROSLAV KLOSE

At 31 you still have a number of years ahead of you in football. However, after lifting the World Cup trophy with Germany in 2014, Philipp Lahm decided to call time on his international career and focus on club football with Bayern Munich. The versatile full-back made 113 appearances for his country and was joined by fellow centurions Per Mertesacker and Miroslav Klose – whose tally of 71 international strikes is a German record – in switching focus to domestic matters.

MARION BARTOLI

A first grand slam at Wimbledon in 2013 appeared to be the breakthrough moment for a 28-year-old Marion Bartoli, but reality proved very different. The Frenchwoman defeated Sabine Lisicki – who had overcome pre-tournament favourites Serena Williams and Agnieszka Radwanska – in the All England Club final, but announced her retirement during the Western and Southern Open just 40 days later due to persistent injuries. She attempted a comeback in 2018 but continued setbacks and injuries curtailed those plans.

NICO ROSBERG

Nico Rosberg had engaged in several intense battles with Lewis Hamilton before finally getting the better of his Mercedes team-mate to become Formula One world champion in the 2016 season. Still only 31, Rosberg had potentially several more years in F1 but the German instead opted to depart having reached the pinnacle of his sport.

Iga Swiatek claimed back-to-back WTA 1000 titles as she captured the Indian Wells Open crown after defeating Maria Sakkari 6-4 6-1.

Winning her 11th successive match, the Pole added to her triumph in Doha last month after prevailing in one hour and 20 minutes.

Swiatek subsequently climbed to a career-high second in the WTA rankings; making her the first Polish player to do so since Agnieszka Radwanska in July 2012.

The 20-year-old also claimed her fifth career title; becoming only the fifth woman to reach that tally before her 21st birthday after Kim Clijsters, Venus Williams, Serena Williams and Svetlana Kuznetsova.

"After playing so well in previous tournaments, I didn’t know it was possible for me to play that well for that long," said the former French Open champion, who claimed her second successive win over Sakkari having also prevailed in the Qatar Open semi-finals.

"I want to congratulate Maria. Every match against her is a great battle. I know that we've already started a cool rivalry. 

"I think it's going to last for 10 more years, so it's going to be exciting, and I’m sure we're going to play many more finals.

"I want to thank my team; they're doing an amazing job calming me down and getting me to the place where I'm more confident and developing my tennis."

The two finalists struggled to settle during the opening set; both hitting five double-faults as six of the first seven games went against the serve.

But 12 unforced errors to her opponent's seven proved crucial for Sakkari, who had only been broken seven times in her five previous matches, as third seed Swiatek drew first blood after 45 minutes.

Losing only her second set of the week, sixth seed Sakkari had been beaten on all three occasions in 2022 when losing the opener.

Meanwhile, Swiatek had not dropped a set since her fourth-round victory over Angelique Kerber, and built on that momentum as she dominated the second.

The former Roland Garros champion broke her opponent twice more, as she only required an additional 35 minutes to wrap up victory; a sweeping forehand sealing the deal.

Iga Swiatek defeated Simona Halep 7-6 (8-6) 6-4 at the Indian Wells Open on Friday, progressing to the final and extending her winning streak to 10.

The Polish world number four came back from a break down in each set - as well as saving two set points in the first-set tiebreak - to level her head-to-head record with Halep at 2-2.

After taking out the WTA 1000 tournament in Doha last month, Swiatek has not had it all her way this week in California. Aside from a 6-1 6-0 trouncing of Madison Keys, the 20-year-old had to fight from a set down in her opening three matches.

Following a tight first set, Halep won three games in a row to take a 4-2 lead, but it was here Swiatek started to open up on return of serve.

She was ultimately able to capitalise on Halep's second serve, winning 14 of a total 21 points when given a second look, to earn five service breaks for the match.

Swiatek is now at least guaranteed to reach a career-high world number three ranking with, and a win in the final would move her to number two, only behind Ashleigh Barty.

She will meet Maria Sakkari in the final on Sunday, who broke down in tears after her hectic 6-2 4-6 6-1 win over Paula Badosa in the late match.

Despite Badosa having a higher first-serve rate than her opponent in the first set at 53.9 per cent, Sakkari was all over the second serve, winning nine out of a total 12 points.

After powering through the first set with flat hitting, the Greek world number six lost momentum in the second and forced play with rushed shot selection after getting broken early.

She still managed one of the shots of the match in trying to save that break of serve, scrambling across court to hit an underarm pass down the line.

Badosa kept her composure on serve to take the second set, winning 21 out of 29 points at an improved 72.9 per cent. Sakkari regrouped and exhibited her unique court coverage, however, taking the win after getting an early break.

Sakkari immediately broke down in tears afterwards, upon making her first WTA 1000 final and defeating the defending champion at Indian Wells.

The Grand Slam Board has announced that first-to-10 tie-breaks will conclude the final sets of all four majors with immediate effect.

Starting with May's French Open, the decision is being adopted on a trial basis with the aim of providing "greater consistency" to the rules when matches go the distance.

Prior to Wednesday's announcement, the French Open, Australian Open, US Open and Wimbledon each had their own rules when games went to a deciding tie-break.

The Australian Open is the only grand slam to already employ the first-to-10 rule at 6-6.

Wimbledon previously played first-to-seven at 12-12, while the US Open played a first-to-seven at 6-6.

There has not previously been a deciding tie-break at Roland-Garros, with all matches continuing until a player secured a two-game lead in the decider.

A statement released on behalf of Grand Slam Board members Jayne Hrdlicka, Gilles Moretton, Ian Hewitt and Mike McNulty confirmed the changes.

It read: "The Grand Slam Board's decision is based on a strong desire to create greater consistency in the rules of the game at the Grand Slams, and thus enhance the experience for the players and fans alike.

"This trial, which has been approved by the rules of the tennis committee governed by the ITF, will apply to all Grand Slams across qualifying, men's singles and doubles, women's singles and doubles, wheelchair and junior events in singles, and will commence at the 2022 edition of Roland-Garros."

The rule change will be reviewed after a full Grand Slam year and will remain in place should it be deemed a success.

The tweaks to the current format will ensure no repeat of John Isner's marathon battle with Nicolas Mahut at Wimbledon in 2010, which the American edged 70-68 in the final set of their first-round match.

Paula Badosa went a step closer to defending her Indian Wells Open title as she ended Leylah Fernandez's run to reach the quarter-finals.

Badosa was calm under pressure against last year's US Open runner-up, saving five out of the six breakpoints she offered up in a 6-4 6-4 success.

Matters were less routine for third seed Iga Swiatek, who held her nerve to come back from a set down against three-time major champion Angelique Kerber.

Breakpoints were contested in six of the match's first eight games and Kerber made the big points count, but Swiatek went on to triumph 4-6 6-2 6-3.

Swiatek, 20, showed grit beyond her years as she broke Kerber's serve four times in the second set, cleaning up her first-serve percentage while the German was only able to win 31 per cent of her successful first-serves (4-13).

Both women hit over 70 per cent of their first-serves in the final set, with the difference coming down to the return game, where Swiatek won half of her return points (12-24), with Kerber struggling (5-22).

Swiatek will face American Madison Keys, who defeated Harriet Dart in a brisk 69 minutes, while Badosa goes up against Veronika Kudermetova, who overcame Naomi Osaka in contentious circumstances earlier in the tournament.

WTA chairman Steve Simon declared Russian tennis players must not be penalised for their country's "authoritarian leadership" amid concerns they could be frozen out of top tournaments.

The ATP and WTA tours decided Russian and Belarusian players should not be allowed to represent those nations while the crisis in Ukraine continues, with stars such as Daniil Medvedev currently playing under a neutral flag.

The respective tennis tours have also cancelled plans to visit Russia in the near future.

United Kingdom sports minister Nigel Huddleston suggested on Tuesday that US Open champion Medvedev and fellow Russians could be blocked from playing at Wimbledon unless they make a stand against president Vladimir Putin.

But WTA head Simon insisted Russian and Belarusian tennis players should be able to continue featuring on the tour, despite a number of other sports banning such athletes.

"I can tell you that we have never banned athletes from participating on our tour as the result of political positions their leadership may take," Simon told BBC Sport.

"So it would take something very, very significant for that to change, but again we don't know where this is going."

If national governments impose preventive measures on Russian and Belarusian stars, Simon acknowledged there is little he can do to combat such rulings.

"I feel very, very strongly that again these individual athletes should not be the ones that are being penalised by the decisions of an authoritarian leadership that is obviously doing terrible, reprehensible things," Simon said.

"We are hopeful that they will refrain from that because I think there are an awful lot of other issues that go with it. I'm hoping that we continue with the sanctions, we continue doing everything we can to get peace, but again these people are the innocent victims of that, and being isolated as a result of these decisions I don't think it's fair."

Daniil Medvedev and fellow Russian tennis stars could be banned from playing at Wimbledon unless they denounce president Vladimir Putin.

That was confirmed by UK sports minister Nigel Huddleston on Tuesday, as he told a parliamentary committee there were concerns about Russian representation in sport.

With Russia's military invasion of Ukraine ongoing, Huddleston warned it would not be appropriate for anyone to be seen to be flying the flag for their homeland, or showing any support for Putin's regime.

Speaking at a Digital, Culture, Media and Sport Committee session, Huddleston was asked about Wimbledon and Medvedev, the current men's world number one player and reigning US Open champion.

Huddleston said: "We are looking and talking to various sports about this and what the response and requirements should be there. Absolutely, nobody flying the flag for Russia should be allowed or enabled."

He added: "We need some potential assurance that they are not supporters of Vladimir Putin and we are considering what requirements we may need to get some assurances along those lines.

"In short, would I be comfortable with a Russian athlete flying the Russian flag? No."

Asked about the All England Club, which hosts Wimbledon, Huddleston said: "We are in discussions."

Russia has four players in the men's top 30, and three in the women's top 30.

They are playing under neutral flags at present, after the ATP and WTA tours decided Russian and Belarusian players should not be permitted to represent those nations while conflict continues in Ukraine.

Wimbledon runs from June 27 to July 10 this year, with a week of qualifying preceding the tournament.

Demanding each player from Russia directly comes out against president Putin would be going a step beyond what is currently required.

Huddleston said: "We are looking at this very issue about what we do with individuals, and we are thinking about the implications of it, because I don't think people would accept people very clearly flying the Russian flag, in particular if there is any support and recognition for Putin and his regime."

Speaking last week at Indian Wells, Medvedev spoke about being allowed to continue to play on the tour.

"It's definitely not for me to decide. I follow the rules. I cannot do anything else," he said. "Right now the rule is that we can under our neutral flag.

"I want to play my favourite sport. Until I have the chance to do it, I'm going to be there to try to play for the fans, play for other people, for myself also of course.

"Also I think tennis is a very individual sport, so far what we are seeing [being sanctioned] are more national teams or some team sports. Let's see how the situation evolves."

World number five Anett Kontaveit slipped out of the Indian Wells Open after a 3-6 7-5 7-6 (7-5)  loss to Marketa Vondrousova.

Kontaveit was the second-highest seed remaining in the tournament entering Monday's play, and appeared to be on her way through to the fourth round after breaking twice in the opening set.

Yet Vondrousova got the better of her Polish opponent in a topsy turvy second set, forcing a decider that starter in frantic fashion, with a concession of serve in each of the opening five games.

Vondrousova held to end that street yet was pulled back to 4-4 by a resurgent Kontaveit, though the Czech world number 33 eventually closed the match out at the fourth time of asking in the tie-break to tee up a clash with Veronika Kudermetova.

Emma Raducanu knows she must "get stronger" after losing to Petra Martic in the third round of the Indian Wells Open.

Martic came from a set down to beat US Open champion Raducanu 6-7 (3-7) 6-4 7-5 on Sunday.

Teenager Raducanu has been troubled by a back injury and an issue with her hip.

The Brit says she was hampered at Indian Wells, but is confident she will be fit for the Miami Open next week.

"I think it's just part of not playing and having so much stop start and having five, six days to prepare for matches and then playing at that intensity,” she said.

"It was a tough one not being able to serve full out so I was having to work so hard just to hold.

"I've just got to get stronger. I've had it for the last few days, just a product of training hard and probably the last match was pretty intense too and it didn't settle down.

"When you are crossing your fingers to hold serve every time, it's tough. I couldn't really drive up and I was kind of struggling to turn and reach.

"The margins were so small. I should be good for Miami, for sure."

Andy Murray has expressed his sympathy for Naomi Osaka over the abuse she was subjected to at Indian Wells but says athletes must deal with it.

Osaka was reduced to tears as she crashed out of the Indian Wells Open with a 6-0 6-4 third-round defeat to 21st seed Veronika Kudermetova on Saturday.

A member of the crowd could be heard shouting "Naomi, you suck" after the four-time grand slam champion had been broken in the first game of the match.

Osaka approached the chair umpire to report the incident and held further discussions with the court supervisor after being insulted again.

Murray says there is no place for such conduct, but believes players must be able to ignore it.

He said: “It's a difficult one. I've often thought watching certain sports, I wouldn't say I've often seen it loads in tennis … but if I watch a football or a soccer match and a player's going to take throw-in or a corner kick and the crowd are just hurling insults at those individuals.

"I always think, how is that allowed? Like, you can't do that. If you're doing that to someone when you're walking down the street or in any other sort of work environment, that's obviously not tolerated.

"I've played in certain atmospheres as well myself in tennis, like Davis Cup atmospheres, away from home, especially where the atmosphere's intense, and sometimes things are said and it's not that comfortable.

"The people that come to watch, you want them to be there and supporting the players and not making it more difficult for them. I don't know, but it's also something that's always just kind of been part of sports as well."

He added: "If you go and watch a basketball match, for example, and a player's taking free throws, I would say like almost every basketball match I've been to one of the players has been heckled by the crowd as well

"While it's wrong for those individuals to be doing it, the athletes obviously have to kind of be used to that as well or be able to deal with that too, even though it's not pleasant.

"I feel for Naomi, that obviously it upset her a lot, but it’s always been something that's been part of sport, I guess, as well.

"You have to be prepared for that in some ways and be able to tolerate it because it does happen regularly across all sports."

Two-time major winner Simona Halep secured a spot in the Indian Wells Open last 16 with a strong 6-3 6-4 victory over 16th seed Cori Gauff on Sunday.

Halep, who is aiming to rebuild her ranking in 2022 after an injury-hit second half of last year, was excellent with her return, particularly on Gauff's second serve to gain the edge.

The Romanian saved all four break points generated by Gauff, while she converted three of the nine break points that she created.

Halep, who started the year with victory at the Melbourne Summer Set 1 before a last-16 loss to Alize Cornet at the Australian Open, needed only one hour and 16 minutes to seal her progress.

She will next play Romanian compatriot Sorana Cirstea after the 26th seed won 5-7 6-1 6-0 against lucky loser Anna Kalinskaya.

Last year's US Open champion and British 11th seed Emma Raducanu was bundled out by Croatian world number 79 Petra Martic 6-7 (3-7) 6-4 7-5.

Raducanu had served for the match in the final set but the Croatian won the final three games. Martic triumphed in two hours and 46 minutes, reaching the last 16 at Indian Wells for the second time in her career.

Martic will face 28th seed Liudmila Samsonova who triumphed 6-4 7-6 (7-4) over Danka Kovinic.

Third seed Iga Swiatek came from a set down to win 6-7 (3-7) 6-2 6-1 over Clara Tauson in two hours and 18 minutes.

Swiatek has won seven straight matches and is unbeaten at WTA 1000 events this season, having triumphed in Doha last month.

The Pole will take on three-time major winner Angelique Kerber in the last 16 after the German won comfortably over Daria Kasatkina 6-2 6-1.

American 25th seed Madison Keys got past countrywoman Alison Riske 7-6 (7-4) 6-1, setting up a fourth-round meeting with British qualifier Harriet Dart who beat Kaia Kanepi in straight sets.

An emotional Naomi Osaka says being targeted by a heckling spectator during her loss to Veronika Kudermetova reminded of abuse the Williams sisters were subjected to at the Indian Wells Open.

Osaka was reduced to tears as she crashed out with a 6-0 6-4 third-round defeat to 21st seed Veronika Kudermetova at Indian Wells on Saturday.

A member of the crowd could be heard shouting "Naomi, you suck" after the four-time grand slam champion had been broken in the first game of the match.

Osaka approached the chair umpire to report the incident and held further discussions with the court supervisor after being insulted again.

Serena and Venus Williams were subjected to verbal abuse at the prestigious tournament in the Californian desert back in 2001.

The legendary siblings' father, Richard Williams, claimed he had been racially abused at Indian Wells, while Venus Williams said she "heard whatever he heard".

Former world number one Osaka said while trying to hold back the tears after her exit: "I've been heckled before and it didn't really bother me.

"But being heckled here... I've watched videos of Venus and Serena get heckled here and if you've never watched it, you should watch it.

"I don't know why, but it went into my head and got replayed a lot. I just want to say thank you and congratulations [to Kudermetova]." 

Serena Williams boycotted the competition for 14 years before making her Indian Wells return in 2015.

Naomi Osaka was brought to tears by a heckling spectator during her Indian Wells Open match with Veronika Kudermetova before going on to lose 6-0 6-4.

The incident happened after Osaka had been broken by Kudermetova in the first game, with someone in attendance reported to have yelled "Naomi, you suck".

Four-time grand slam winner Osaka, competing in her first tournament since January's shock early Australian Open exit, appeared to ask the chair umpire to take action.

Osaka initially put that unneeded distraction behind her by taking the next point, but she wasted two break opportunities and Kudermetova successfully held to move 2-0 ahead.

The 24-year-old was in tears as she prepared to serve her next game and held further discussions with the court supervisor after going 3-0 down.

She could not recover and, after losing the first set 6-0, Osaka suffered the only break of serve in the seventh game of the second set to lose the contest fairly resoundingly. 

Kudermetova will now face Marie Bouzkova for a place in the last 16 after the Czech recovered to see off home hopeful Jessica Pegula 5-7 6-2 6-0.

Two-time champion Victoria Azarenka also made it through on Saturday with a 6-3 7-5 victory over lucky loser Astra Sharma, setting up a meeting with Elena Rybakina.

Leyla Fernandez saved four match points against Amanda Anisimova in a dramatic match that came to an end when the American retired through illness.

After losing the opener 6-2, Fernandez took the second set to a tie-break but felt unable to continue. Anisimova will meet Shelby Rogers in a rematch of last year's last-16 encounter.

Angelique Kerber and Maddison Keys each required three sets to reach the third round of the Indian Wells Open, while Coco Gauff held off Claire Liu to advance on Friday.

Number 15 seed Kerber was handed a banana skin tie of sorts against Zheng Qinwen and was made to work hard for her 6-2 5-7 6-4 victory against the rising Chinese star.

Zheng battled back with three breaks of serve in the second set to level up and led 4-1 in the decider, but her opponent dug deep to prevail in a time of two hours and 18 minutes.

Daria Kasatkina awaits Kerber – who had not previously won this calendar year – after the Russian beat Katie Volynets 6-4 4-6 7-5 earlier in the day.

Keys was also pushed all the way in her clash with Misaki Doi before coming out on top 6-4 3-6 6-1 to set up a meeting with Alison Riske in round three.

The Australian Open semi-finalist struggled in the second set after holding her serve throughout the first, though she had enough quality to see off her Japanese opponent.

Gauff had less trouble against fellow American Liu, advancing in a little over an hour to reach the third round, the stage in which she was eliminated on her debut here last year.

She will take on former world number one Simona Halep on Sunday, the day she turns 18, in a rematch of their last-16 showdown from Wimbledon three years ago.

Emma Raducanu and Iga Swiatek are among the others already through to the last 32 in California.

Alison Riske produced a breathtaking comeback to beat Garbine Muguruza at the Indian Wells Open, turning around an apparent lost cause after losing the first nine games of the match.

Muguruza, who won the WTA Finals title at the end of last season, was cruising at 6-0 3-0, but 31-year-old American Riske, despite tossing her racket in frustration, refused to give up. Incredibly, she won 12 of the next 13 games to reach the third round at the expense of the world number nine.

"After the first set, it literally could not get any worse," Riske said in her on-court interview following a 0-6 6-3 6-1 success.

"So if I could try to get two balls in the court we might get somewhere. I was just trying to hang in there. I've played Garbine many times before and it's always been a battle."

This was Riske's fifth match against Spanish star Muguruza, and despite losing the first two of those, she had since beaten the two-time grand slam winner twice, albeit most recently at the 2019 US Open.

"I felt if I could get in there a little bit, I was going to have my chances," Riske said. "I know I've beaten her before, and if I could just bring out some of my game, good things were going to happen."

It was world number 53 Riske's 10th career victory against a player ranked in the top 10.

British player Harriet Dart pulled off a shock win over Ukrainian Elina Svitolina, as the world number 122 snatched a 2-6 6-3 6-3 victory over the 12th seed.

Three of the biggest names in the draw took the long route through to the last-32 stage, with Emma Raducanu, Simona Halep and Iga Swiatek taken to a deciding set in their opening matches, having benefited from first-round byes 

Raducanu fended off Caroline Garcia 6-1 3-6 6-1, while Halep was a 6-2 4-6 6-2 winner against Ekaterina Alexandrova, the Russian who is playing under a neutral flag.

Polish third seed Swiatek put a slow start behind her to beat Ukrainian Anhelina Kalinina 5-7 6-0 6-1 and is looking to build on her recent Qatar Open triumph. She said: "I'm pretty happy I could turn my head on to fight mode and stay focused, because that was the key I guess."

Last year's Wimbledon runner-up Karolina Pliskova bowed out, the Czech seventh seed losing 2-6 7-5 6-4 to Danka Kovinic of Montenegro.