Dancing nimbly in the darkened hall of a Nairobi boxing gymnasium, several men in soaked T-shirts and tracksuit bottoms pummel punchbags.
Almost unnoticed among the dozens of grunting bodies is Congestina Achieng, Kenya's top female boxer and the first African woman to hold an international title.
In December, the middleweight nicknamed "Hands of Stone" by the local press beat Uganda's Fiona Tugume on a unanimous points decision to win the vacant Women's International Boxing Federation (IBF) title.
The win secured Achieng a number five ranking in the women's IBF and gave her a yearning for wider glory.
The woman from the Kenyan slums now wants a shot at one of her heroes, Laila Ali, daughter of boxing great Muhammad and the Women's International Boxing Association (WIBA) super-middleweight champion.
"I can crush her," Achieng, a 27-year-old single mother, said of the American. "My left hook is so strong. She's a human being like me so what's there to fear?"
The self-confessed tomboy boasts 10 technical knockouts since picking up her gloves in 2001.
With her cropped hair and lithe moves, Achieng looks like any one of the young men working out in the local police gym, where drops of sweat splatter the linoleum floor.
"I discovered that working out with guys helps boost my morale so whenever I meet an opponent I am confident of winning the fight," said Achieng.
"I regard them as my training partners and not as men."
Young boys poke their heads through the cracked glass panels of the gym door, mesmerised by the boxers whipping skipping ropes through the air and clenching their teeth as they do push-ups on their knuckles.
In a culture where women often play submissive roles, Achieng's success in the ring has earned her respect from the neighbourhood boys and police officers who train beside her.
"We can't deny women boxers, it's their sport too," said Eric Onyango, who was assisting with the training.
"When she spars with some of the guys she beats them, she knocks them out. She's as good as any man."
Asked if she has ever been provoked into street fighting, Achieng breaks into one of many wide smiles.
"I'm very polite," she said, shaking her head. "It's only for the ring."
Better known for its athletics than boxing, Kenya produced welterweight Robert Napunyi who became the first African boxer to win a gold medal at the Olympics in 1988.
However, his premature death at the age of 27 during a fight in the United States dampened homegrown enthusiasm for the sport.
Despite her new-found status, Achieng struggles to make ends meet like the majority of Kenyans who survive on less than $1 a day.
"I can't afford the right foods and sometimes I don't even have the bus fare to go for training," said Achieng, who earns about $250 for every fight.
With only a few bouts every year, she still lives in a one-roomed shack in the middle of Nairobi's teeming, litter-strewn Mathare slum.
Most boxers in Africa, the world's poorest continent, share Achieng's cashflow problems.
Government support for training facilities and equipment is limited. Reliable boxing promoters are rare, which means prize money from fights is hard to come by.
Ochilo Ayacko, Minister for Culture, Gender and Sports, has appealed to the private sector to promote sports.
Achieng said she boxed for the love of it.
"My dream is to become world champion, make a name for my country and win more belts," she said.
"Boxing is my life -- there's nothing else I can do. You have to commit yourself, be disciplined, focus on the game."
(Additional reporting by Donna Omulo)