Graca Machel. File picture:Nokuthula Mbatha/African News Agency/ANA

Johannesburg - "One of the best ways we can celebrate Madiba's centenary and uphold his legacy is for each one of us to commit to do our part in very meaningful ways."

These were the words of late statesman Nelson Mandela's widow and human rights activist Graca Machel, who announced the winner of the inaugural Global Citizen World Leader Prize. 

Machel was among the many world leaders, activists, celebrities and dignitaries who celebrated Mandela's centenary and urged citizens to continue taking action to defeat poverty. 

Machel expressed joy at seeing thousands of young people taking action and contributing in their own way. 

"I am so pleased to see millions of engaged citizens around the world celebrating Madiba and taking action to end extreme poverty," she said. 

Machel then announced the winner of the inaugural Global Citizen World Leader Prize, Norway Prime Minister Erna Solberg.

Joining Machel were Mandela's daughters Makaziwe and Zindzi Mandela, who not only celebrated their father's legacy and championing of women's rights but also late stalwarts Winnie Madikizela-Mandela and Albertina Sisulu. 

International supermodel Naomi Campbell also paid tribute to Mandela, who she fondly said she'd regarded as both a hero and her grandfather. 

"Long live the spirit of Mandela," she said.

Earlier, crowds were treated to performances from a mix of local and international entertainers including Usher, Chris Martin, Pharrell Williams, Ed Shereen, Tiwa Savage, Wizkid, D'banj and Sho Madjozi. 

Still to perform are the Cassper Nyovest and international superstars Beyonce and Jay-Z.