On a giant, glove-shaped stage, fans were urged to focus on the late singer's music rather than his sudden death.
Three-fifths of the original Jackson 5 - Tito, Marlon, and Jackie - wowed the crowd. Other performers included Christina Aguilera, Gladys Knight, Cee Lo Green and Leona Lewis.
Jackson died in June of 2009 at age 50 while he was preparing for a string of comeback concerts in London.
Fans and performers called the four-hour concert a counter-act to the courtroom drama now unfolding in downtown Los Angeles, where the singer's doctor, Conrad Murray, is currently on trial for involuntary manslaughter.
"He shared his soul with all of whom would listen," La Toya Jackson said, "and that is a mark of a truly, truly great artist. And he was an exceptionally great and a wonderful entertainer, as you all know."
Despite sluggish ticket sales and some disagreement within the Jackson family itself, many fans in attendance said they wouldn't have missed the show for anything.
"I wish I had attended one of his concerts, but this is the least I can do to salute and give a tribute for the king, undisputed King of Pop," one fan said.
Jackson's mother, Katherine, was in the audience, but siblings Jermaine, Randy and Janet were not. They said it was wrong to hold the show at the same time as the involuntary manslaughter trial of Jackson's doctor.