'We have exhausted all options for reform through dialogue, and the governing bodies have left us no choice but to seek accountability through the courts.'
French veteran Richard Gasquet was also among eight men given wild-card entries.
Zverev and Shelton tested each other in a high-quality encounter before the world number three played a near flawless tiebreak to clinch the match in little over two hours and stretch his career win-loss record over the American to 3-0.
Nagal's career maintained an upward spike when he became the 10th player from India to break into top 100 in ATP rankings.
A summary of sports events and sports persons, who made news on Tuesday
Rohan Bopanna and his Australian partner Matthew Ebden sailed into the men's doubles final at the Miami Open.
Top seed Carlos Alcaraz of Spain and No. 8 seed Hubert Hurkacz of Poland will clash in the ABN Amro Open semi-finals on Saturday after both posted victories on Friday in Rotterdam, Netherlands.
Eighth seed Machac, who won gold in mixed doubles at the Paris Olympics, became the third player from his country to win an ATP 500 title, following Tomas Berdych and Radek Stepanek.
Jeevan Nedunchezhiyan and his partner Vijay Sundar Prashanth clinched their maiden ATP title together, winning the Hangzhou Open men's doubles event, while Yuki Bhambri and his French partner Albano Olivetti finished runners-up at the Chengdu Open
Defending champion Jannik Sinner swept past Felix Auger-Aliassime 6-0, 6-2 on Thursday to reach the Cincinnati Open semi-finals, the world number one extending his hardcourt winning streak to 25 matches.
Cousins Valentin Vacherot and Arthur Rinderknech will meet in the Shanghai Masters final after pulling off stunning upsets of former champions Novak Djokovic and Daniil Medvedev in the semifinals on Saturday.
Jannik Sinner has decided not to take part in this year's Davis Cup Finals with reigning champions Italy confirming his absence in Monday's team announcement, while world number one Carlos Alcaraz will represent Spain at next month's competition.
Djokovic has spent more than 400 weeks at number one and now sits fifth in the rankings
18-year-old Carlos Alcaraz of Spain became the youngest to clinch an ATP 500 title at the same event on Sunday when he defeated Diego Schwartzman in the final of the Rio Open.
India's top-ranked tennis player Sumit Nagal was ousted by Pedro Cachin of Argentina in the pre-quarter-finals of the Braunschweig ATP Challenger, in Braunschweig, Germany, on Wednesday.
Sumit Nagal registered a straight-sets win over Argentine qualifier Nicolas Kicker.
Jannik Sinner had to dig deep to get the better of Auger-Aliassime in the second semi-final.
'I have no idea what's happening right now, I'm not in a dream, it's just crazy. I'm just so happy with my performance these past two weeks.'
India's new hero Somdev Devvarman climbed up two places to 131 in the latest ATP rankings while Sania Mirza dropped two spots to 65 in the WTA list.
He will surpass Roger Federer's record as the oldest No. 1 in ATP Rankings history on Sunday when he will be 36 years and 321 days old.
India's Yuki Bhambri and his French partner Albano Olivett clinched the men's doubles title at the Swiss Open ATP Tour tennis tournament with a hard-fought win over Ugo Humbert and Fabrice Martin in the final in Gstaad
Factbox on Italy's Jannik Sinner, who beat Germany's Alexander Zverev 6-3, 7-6(4), 6-3 in the Australian Open final
Mboko saved a match point against Kazakh ninth seed Rybakina in front of adoring home support
Djokovic to face World number 204 Valentin Vacherot next.
'The ability for players of any nationality to enter tournaments based on merit, and without discrimination, is fundamental to our Tour.'
Jannik Sinner became the first Italian to win the ATP Finals title following a dominant 6-4, 6-4 victory over American Taylor Fritz.
Iga Swiatek's maiden triumph at the US Open extended her lead to almost twice as many points as the second-ranked Ons Jabeur
France's Boisson wins first WTA title in Hamburg
He also overtook his career-best 65-season win tally of 2023 with this win.
But the big question that keeps striking the mind is, if Indian tennis system can actually claim this win as its own. The answer is: partially.
Sumit Nagal on Monday dropped out of the much-desired bracket following a string of poor show
Dhakshineswar shines on debut, Nagal makes winning return; India take 2-0 lead against Switzerland
The Indian jumped six places following his runner-up finish at the Perugia ATP Challenger tournament on Sunday.
Rohan Bopanna and Sumit Nagal have secured their Paris Olympics 2024 quotas for India
'I think he's bringing a fresh look to my game and I'll be able to benefit from that, no doubt, on the court. But also that champion mentality he has, I'm sure we'll match very well.'
American lucky loser Reilly Opelka put up an intense battle to stun top seed Daniil Medvedev 7-6(5), 7-6(5) and reach the semi-finals in Den Bosch on Friday.
Factbox on Carlos Alcaraz, who beat Alexander Zverev
Maria Sharapova was officially inducted into the International Tennis Hall of Fame on Saturday night in Newport
Sasikumar Mukund, who was banned by AITA on disciplinary grounds, is back as India's best-ranked player for the World Group I Play-off tie against Togo, starting on Saturday.
Eqbal and Faisal's recent success saw him conquer Fardeen Mohammed and Abhinansu Borthakur 6-0, 6-2 in the men's doubles final to win the title.