The anti-apartheid icon walked into the tent with his successor to the South African presidency, Thabo Mbeki, and African National Congress leader Jacob Zuma, stopping to personally greet some of the 500 guests as he made his way to the head table.
The guests, many dressed in traditional beaded cloths, animals skins and feather headdresses, stood and cheered while a Xhosa choir sang: "Here is our hope!"
Wearing, an intricately patterned shirt in shades of brown, Mandela looked relaxed and cheerful as he listened attentively to the accolades being heaped on him.
Mbeki called Mandela a "great liberator." Zuma said the gathering was a celebration of "a life and legacy of a father, grandfather, comrade, warrior, soldier, nation builder and statesman."
Former Zambian President Kenneth Kaunda caught the festive mood with a tuneful solo of "Happy Birthday," followed by a teasing verse: "How old are you? State secret!" Then the 84-year-old Kaunda jogged over to shake Mandela's hand.
The event also marked the 10th anniversary of his marriage to child rights activist Graca Machel and - despite the large number of guests - had a feeling of an intimate family affair.
Flowers at the head table were arranged in vases of tin, a traditional material for 10th anniversary gifts, and the couple sat close together, nodding and clapping appreciatively as family members gave moving tributes.
"This birthday celebration is one of the very small ways that we as your family can show our love, respect and appreciation for all you have done," said one of Mandela's granddaughters, Nandi Mandela.
Machel's daughter Josina said the couple symbolized hope. "The two of you have taught us a lot about the virtues of love," she said.
In the climax of the afternoon, master of ceremonies and lawmaker Bantu Holomisa toasted the couple. "All of you join me in wishing them both all our love, happiness and long life," he said. "Long life!"
To the sound of ululating, Mandela was presented with an aluminum-bound album of family photographs and testimonials, compiled by his children and grandchildren.
Mandela beamed with pleasure as he and Machel eagerly tore off the wrappings and ribbons, surrounded by grandchildren who also assisted him in blowing out the candles on a large cake. The cake had nine gold candles to mark Mandela's birthday and 10 silver ones to mark the anniversary.
Eager to thank his guests, Mandela rose to his feet and spoke for a few minutes with his characteristic self-deprecating humor.
"As you know I am not a speaker at all, and I am not going to make any exception on this occasion, except to say thank you for all you have done for me," he said.
Mandela was imprisoned for nearly three decades for his fight against apartheid. He was released in 1990 to lead negotiations that ended decades of racist white rule, then was elected president in South Africa's first democratic elections in 1994.
He completed his term in 1999 and did not run again, but has continued to take a leading role in the fight against poverty, illiteracy and AIDS in Africa. Age has slowed him in recent years, but many still remain in awe of his stamina. Just last month, he was the honored guest for a huge charity concert in London's Hyde Park.
"I would say that for a 90-year-old man who has been through what he has been through, he is in exceptional shape," one of his doctors, Peter Friedland, said at the party Saturday.
Mandela looked and sounded vigorous Friday when he gave a brief interview to a small group of reporters from The Associated Press and other media, his first such exchange in several years.
During Friday's interview, he expressed deep concern about the poverty that still grips wide swaths of South Africa and said the wealthy must do more.
While Saturday's occasion was celebratory, there were also a few somber moments.
Nandi Mandela called on her grandfather's fans to emulate him by "making a difference in your own communities."
"This is one of the gifts you can give him," she said as her grandfather nodded.
George Bizos, a lawyer who defended Mandela and other anti-apartheid leaders during the era of white rule, urged young and old to try and understand what his old friend stood for.
"It's the solution to the problems that are facing the country, facing the continent, facing the world," he said.
