JOHANNESBURG – Tens of thousands of people sang, cheered and cried as the flag-draped casket of anti-apartheid activist Winnie Madikizela-Mandela was escorted from her official funeral on Saturday, after supporters defended her complex legacy with poetry and anger. Thunder rumbled and it began to rain as the casket left the 40,000-seat stadium – a blessing, witnesses said. Heads of state joined the five-hour celebration of the powerful figure who will be buried as a national hero following lively debate over how she should be remembered after her death on April 2 at age 81. Often called the "Mother of the Nation" and "Mama Winnie," Madikizela-Mandela fought to keep South Africa's anti-apartheid struggle in the international spotlight while her husband, Nelson Mandela, was imprisoned. "Long before it was fashionable to call for Nelson Mandela's release from Robben Island, it was my mother who kept his memory alive," elder daughter Zenani Mandela-Dlamini said as the crowd erupted in cheers. Many South Africans have stood up for Madikizela-Mandela's memory against critics who characterized her as a problematic figure who was implicated in political violence after she returned from years of banishment in a rural town. "Proud, defiant, articulate, she exposed the lie of apartheid," President Cyril Ramaphosa said during his tribute.