Mbele Nonhlanhla laced up her silver soccer boots as her coach shouted encouragement to players with creaky knees, stiff backs and labored breathing in a dressing room in South Africa's far north.

At 63, wearing number 10 and sporting brown-dyed hair, the grandmother of seven was far from your typical soccer player when she stepped onto the field for her first international tournament.

"I feel like a superstar," Nonhlanhla grinned, revealing a missing tooth. "They call me the goal machine."

Her team, Vuka Soweto, hails from the renowned Johannesburg township of the same name.

It had joined more than a dozen others from across Africa and beyond to compete at the Grannies International Football Tournament in South Africa's northern province of Limpopo in April.

The four-day "Grannies World Cup" was held in a stadium with sweeping mountain views.

The 30-minute games were played in two halves at a slow, but purposeful pace, between teams from as far afield as the United States, France and Togo.

"It is all about active ageing. Whether we win or lose, it is all about coming here and staying fit," said 62-year-old South African Devika Ramesar, a mother of two and grandmother of five.

Until the week of the tournament, the Liverpool fan had never stepped onto a soccer pitch.

Kenyan striker Edna Cheruiyot only had two months to learn the "long list" of the game's laws before her debut on April 4, when she scored her only goal.

She took selfies to remember her first ever trip abroad and to send to her grandchildren.