The service in his hometown of Louisville capped a daylong final homecoming for Ali, who died at the age of 74 a week ago.
Earlier in the day, a roughly two-hour funeral procession took his body past places where the legendary boxer spent his formative years: his childhood home, his high school, the first boxing gym where he trained.
The Greatest of All Time was then laid to rest early in the afternoon in a private ceremony at Cave Hill Cemetery. Actor Will Smith, who played the title role in the 2001 film "Ali," and former heavyweight champions Lennox Lewis and Mike Tyson were among eight pallbearers, according to organizers.
The burial was the only private portion of three days of events celebrating Ali
that began with a festival Wednesday and Islamic prayer program Thursday. It was just how Ali wanted the funeral plans to be when he laid them out
several years back -- as open as possible so his fans could say goodbye
Friday afternoon's memorial was the main public celebration, held at the 22,000-seat KFC Yum! Center in Louisville. Many of the public attendees started lining up Tuesday for a chance to get tickets.
Ali's widow, Lonnie, spoke eloquently about the inspiration of his legacy.
"He was sure-footed in his self-awareness, secure in his faith, and he did not fear death," Lonnie Ali said.
"As we face uncertainty," she said, "Mohammad's life provides useful guidance."
Two of Ali's children spoke. Maryum Ali was followed by Rasheda Ali-Walsh, who made the crowd smile when she said, "Daddy's looking at us now, right? And saying, 'I told you I was the greatest!' No one compares to you, Daddy."
At the memorial service, eulogies also came from University of Louisville student Natasha Mundkur
and family friend John Ramsey.
Malcolm X's eldest daughter, Attallah Shabazz, came close to tears recalling the man who was the last close connection to her father.
"Having Muhammad Ali in my life somehow sustained my dad's breath for me just a little while longer -- 51 years longer -- until now," she said in her eulogy.
"I am forever grateful that our union on this earth together allowed for me continuum of shared understanding, preserved confidentialities and the comfort of living in his hometown of Louisville, Kentucky, for the past six years."
Shabazz said her father loved Ali as "a little brother, 16 years his junior," and as a trusted friend.
With his remarks coming at the end of the nearly three-hour service -- which was already delayed for nearly an hour -- bewhiskered comedian Billy Crystal joked that he was clean-shaven when it all started.
Crystal said he knew Ali for 42 years, having met him in 1974 when he was just starting out as a standup comedian and by chance was asked to do a routine at an event where Ali was present, and where he performed his impression of the boxer.
The boxer whispered in Crystal's ear that he was his "little brother," a term he used every time they saw each other, Crystal said.
"He was a tremendous bolt of lightning, created by Mother Nature out of thin air," Crystal said.
Closing out the memorial service was former President Bill Clinton, who payed homage to Ali's sense of humor right off the bat:
"I can just hear Muhammad saying now, 'Well, I thought I should be eulogized by at least one president, and by making you last in a long, long line, I guaranteed you a standing ovation."
Ali was able to rise above his affliction with Parkinson's Disease by being a man of both wisdom and faith, Clinton said.
"Being a man of faith, he realized he would never been in full control of his life. Something like Parkinson's could come along, but being free, he realized that life still was open to choices.
"It is the choices that Muhammad Ali made that have brought us all here today in honor and love," Clinton said.
The memorial service embraced many religious faiths including an opening reading from the Quran by scholar and the family's religious adviser, Imam Shakir. A Protestant minister, two rabbis, a representative from the Catholic Church, a representative from the Buddhist religion and Sen. Orrin Hatch (representing the Mormon faith) also spoke.