Ali appeared frail, his body clearly ravaged from Parkinson's disease.
Mr. Frazier's white casket was adorned with the heavyweight title belt he retained by defeating Ali in 1971's "Fight of the Century" and a pair of boxing gloves.
A 100-member choir sang hymns, while ministers urged the crowd to rise and "show their love" for the former champ.
The Rev. Jesse Jackson addressed the gathering, along with other religious leaders from Philadelphia.
The 46-year-old Hopkins remembered Mr. Frazier as someone who was not only a fighter but a vibrant member of the community. He said the courage Mr. Frazier displayed out of the ring served as an example for his own career.
"If you can take a page out of Joe Frazier's book, to get knocked down and get back up," said Hopkins. "Be true to what you believe in and what you do, no matter what you do. . . . There are going to be challenges, and sometimes they look too big to defeat. But if you're Joe Frazier, you're going to put 100 percent in there."
Hopkins said Mr. Frazier never lost his will and determination to be a leader, fighting for causes that Hopkins said weren't always popular or noteworthy.
"When I want to be remembered, I want to be remembered of what Joe Frazier had done," said Hopkins. "If I can do one third of what Joe Frazier has done, then it's only a blueprint for me to leave a legacy."
In his remarks, Jackson drew cheers from the congregation as he chastised the city for not having a statue of Mr. Frazier. He questioned why the city so eagerly celebrated fictional boxer Rocky Balboa and not Mr. Frazier.
"Tell them Rocky was not a champion, Joe Frazier was," said Jackson. "Tell them Rocky's fists were frozen in stone. Joe's fists were smokin'."
On Friday, Mayor Nutter said the city was discussing plans for a lasting memorial with Mr. Frazier's family.
Promoter Don King, wearing an American flag scarf and carrying a small flag, said that working with Mr. Frazier "was a thrill, because he was the embodiment of a heavyweight champion." The promoter of Mr. Frazier and Ali's epic "Thrilla in Manila" said that Mr. Frazier's reserved nature often made him misunderstood.
"He was really fighting for freedom, justice, and equality the same as Ali was doing," said King. "Only he couldn't articulate it as well as Ali. Therefore, he would use it in a competitive style with the courage and invincible spirit."
King said Monday's ceremony should be seen as day of rejoicing because Mr. Frazier lived a good life and was able to fight for what he believed in.
"He thought his way was better than Ali's way, because his way was more moderate," said King.
King said Ali's repeated verbal jabs leading up to their fights stung Mr. Frazier for a long time. The promoter recalled attempting to mediate.
Holmes echoed King's sentiments and said Mr. Frazier never showed the way he truly felt. He said Ali's insults hurt him more than anyone, but Mr. Frazier never talked about it.
"But I will," said Holmes.
Contact staff writer Matt Breen at email@example.com or @matt_breen on Twitter.