Mary Kom is coming up against an opponent even she cannot defeat: at 37 years of age, sooner rather than later, the final bell will toll on her career.
But before that sound rings out, Kom has the chance to add the final chapter to her incredible career by qualifying for a second Olympic Games.
In order to make it to Tokyo 2020, Kom must first come through the Asian/Oceanian Olympic qualifiers which are scheduled to be held in Amman, Jordan from 3-11 March.
Along the way to becoming India's most successful boxer in history, Mary Kom has defied convention and overturned the odds.
So could we see her standing on the podium with yet another medal around her neck at Tokyo 2020?
If the Mary Kom story has taught us anything, don't bet against it.
Kom will arrive for the Olympic qualifiers on the back of her victory over Nikhat Zareen in the Indian national trials for the competition.
The build-up to their final in the 51kg category was a much-hyped one, billed as a 'clash of the ages'.
23-year old Zareen was the rising star in the division, being crowned the national champion earlier in 2019.
20 Feb - 15 Mar 2020
Tokyo 2020 Olympic Qualification Tournaments
Dakar, Amman, London, Buenos Aires, Paris
But when the pair finally met in the ring, Kom let a nation know that the old guard was not ready to stand down just yet with an emphatic 9-1 triumph.
That paved the way for another shot at Olympic glory for a woman who had risen to the top of her sport from relatively lowly beginnings.
Mary Kom's full name is Mangte Chungneijang Mary Kom, and she was born on the 1st March 1983 in a place called Kangathei, situated in the north eastern state of Manipur.
Kom was the eldest of three children and came from a humble background where her father, a tenant farmer, struggled to provide two meals a day to his kids.
Few then would have guessed that one of India's sporting greats was amongst their midst.
But Kom's life was transformed when she found inspiration from fellow Manipur-native Dingko Singh.
Singh became an overnight hero after winning boxing gold for India at the 1998 Asian Games in Bangkok.
His triumph lit a fire in the teenage Kom. But the love for boxing that had been kindled initially had to burn in secret.
Initially she was worried about her father's reaction to her participating in the sport and tried to hide it from her family.
But the passion was too strong, and Mary was too good. The truth had to out.
It did not take long before she began to shine.
Kom's medal record at the Women's World Championships level is nothing short of astonishing.
In total, the Indian boxer has come home with a medal at no less than eight editions of the Championships.
Her first came as a callow 18-year old at the very first Women's World Champs held in Scranton, USA back in 2001.
Boxing at the 48kg level, Kom claimed a silver medal.
The following year saw the start of Kom's golden run as she was crowned world champion for the first time.
Kom was seemingly untouchable, and by 2010 she had won five world titles in a row.
Then came her biggest moment of all: success on the Olympic stage.
With women's boxing making a debut at London 2012, Kom once again found herself as a pioneer for the sport in India.
But with the chance to box for Olympic glory came a change: Kom had to step up a weight class, moving from her customary 46kg to the 51kg category.
She seemed to take the shift in her stride, as she moved through to the semi-finals without much difficulty.
But the home favourite Nicola Adams proved to be too hot to handle: Kom's run was ended.
However, her exploits had earned her a bronze medal and another slice of history had been made.
Following her Olympic moment, more success came her way: Asian Games 2014 gold medal in the 51kg category, Commonwealth Games champion in 2018 after dropping back down to 48kg.
2018 also saw Kom win a sixth gold medal at the Women's World Championships.
That triumph in New Delhi meant that she surpassed Ireland's Katie Taylor to become the only female to have the world title six times.
At last year's World Championships in Russia, Kom claimed a bronze medal to go past Cuban great Felix Savon and become the most medalled world champion ever, as she stood on the podium for a record eighth time.
Outside of the ring too, her achievements were noted.
She has been conferred with the Padma Shri in 2006, the Padma Bhushan in 2013 and the Padma Vibhushan in 2020, the country's fourth-highest, third-highest, and second-highest civilian awards, respectively.
She was also honoured with the Arjuna Award, given to recognise achievement in sports, in 2003 and the Rajiv Gandhi Khel Ratna, the country's highest sporting honour, in 2009.
It is little wonder then that such an incredible life story has been captured in film.
Simply entitled 'Mary Kom', a biopic movie directed by Omung Kumar and starring Priyanka Chopra in the leading role was released in 2014.
"For me, as a woman, Mary's life was extremely inspiring," said Priyanka Chopra, a month before the Mary Kom movie hit the cinema. "She as a person is someone who is feisty, stands up for her rights and fights for what she believes in."
The movie - loosely based on Women's World Championship triumph of 2008 in Ningbo - was a huge commercial success, grossing a little over ₹1 billion in box office collection.
Juggling a work-life balance can be difficult for any parent, but trying to cope as an elite level athlete brings another kind of pressure.
For Mary Kom, children and chasing boxing dreams have had to be combined for the bulk of her sporting career.
Kom's husband is Karung Onkholer Kom, whom she married in 2005.
Two years later she gave birth to twin boys, Rechungvar and Khupneivar.
The couple then welcomed a third son, Prince, in 2013 before adopting their daughter, Neivar Merilyn in 2018.
The boxer has often spoke of the support her husband has given her and their children throughout her career, allowing her to focus on training and competition.
Indeed, it was Kom's husband who pulled her back from the brink of quitting competition.
The Olympic medallist has revealed how she thought about hanging up her gloves after her son Khupneivar was diagnosed with a hole in the heart in 2011.
Only Kom's partner could persuade her to continue to pursue her sporting ambitions.
"My husband pushed me, saying 'you should go, you play and win and come back'. Whatever the responsibility back home, he said he will take care of it."
As one of the elder stateswomen of her sport, Kom is now an ambassador for boxing.
As well as serving as an inspiration for a new generation stepping into the ring, Kom has also been selected as one of the athlete ambassadors for the Olympic qualifiers for Tokyo 2020.
Her role involves giving advice to organisers to ensure the actual tournaments are run as smoothly as possible.
It also means she will be available to talk to other athletes and make sure their interests are kept at heart.
However, Kom's primary concern will be ensuring she secures her Olympic spot.
Having missed out on qualification for Rio 2016, a place at the upcoming Games in Tokyo would give her the perfect platform to sign off in style.
But whatever happens between now and July, Kom's place in the history of Indian sport is assured.
A trailblazing boxer who broke boundaries and set the standards by which future generations of boxers will be measured.
Magnificent Mary, indeed.
Live streaming overage from all the Boxing Olympic qualification events will be available Worldwide at olympicchannel.com and Olympic Channel Apps