Michael Joseph "Prince" Jackson Jr. told jurors his father wanted more time to rehearse and had several tense phone conversations with promoters of his "This Is It" shows that sometimes ended with his father in tears.
The 16-year-old said his father remarked after one of the conversations, "They're going to kill me." He did not elaborate.
The testimony came in a lawsuit claiming AEG negligently hired Conrad Murray, the doctor who was later convicted of involuntary manslaughter for giving Jackson an overdose of the anesthetic propofol.
AEG denies it hired the physician or bears any responsibility for the entertainer's death.
Wearing a black suit with a dark grey tie and his long brown hair tucked behind his ears, Prince testified that he saw AEG Live CEO Randy Phillips at the family's rented mansion in a heated conversation with Murray in the days before his father died. The teenager said Phillips grabbed Murray's elbow.
Phillips "looked aggressive to me," Prince testified.
Michael Jackson wasn't at home at the time and was probably rehearsing, Prince said.
Murray's attorney Valerie Wass and AEG defense attorney Marvin S. Putnam later denied outside court that the meeting Prince described ever happened.
Putnam said Prince would be recalled to the witness stand during the defense case later in the trial.
"I think as the testimony will show when he is called in our defense that's not what happened," Putnam said. "He was a 12-year-old boy who has had to endure this great tragedy."
For the first time, the teenager publicly provided details about the day his father died. Prince testified that he saw Murray performing CPR on his father, who was hanging halfway off a bed. It appeared his dad's eyes were rolled up in the back of his head, Prince told jurors.
Prince's eyes appeared red as he recalled being told by Murray at a hospital that his father was dead.
Prince said he never saw Murray's treatments of his father.
"I was 12. To my understanding he was supposed to make sure my dad stayed healthy," Prince testified.
Prince said none of the household staff was allowed upstairs at the mansion, and the singer kept his bedroom locked while receiving treatments from Murray.
During cross-examination, Putnam played a clip from a deposition of Prince in which the teen said he discovered the bedroom was locked when he and his siblings were playing hide-and-seek and couldn't get inside.
Prince also said his father gave him and his sister Paris a stack of $100 bills on a few occasions to give to Murray. The teen said his father told him that Murray wouldn't take the money from him, and the doctor wouldn't take the full amount from the children.
The teenager said his understanding was that the money was meant to tide Murray over until he got paid by AEG Live.
Prince's grandmother, Katherine Jackson, sat in the front row of the courtroom during his testimony. She held a tissue and removed her glasses several times.
The testimony began with the teenager showing jurors roughly 15 minutes of private family photos and home videos.
He described growing up on Neverland Ranch and showed the panel videos of the property's petting zoos, amusement park and other amenities. After his father's acquittal of child molestation charges, Prince described living in the Middle East, Ireland and Las Vegas.
He told the jury that his father was always working, but the children had no idea he was a global superstar.
"We always listened to his music, but we never knew how famous he was," Prince said.
He said he and his sister Paris-Michael Katherine Jackson watched a video of one of their father's performances and got a sense of his fame when overwhelmed fans were carried from his shows on stretchers.
Prince is the first Jackson family member to testify during the trial, now in its ninth week. Attorneys have said TJ Jackson, who serves a co-guardian to Prince and his siblings, and Taj Jackson, are also expected to take the witness stand. They are the sons of Tito Jackson.
Prince Jackson, his sister Paris and brother Prince Michael "Blanket" Jackson are plaintiffs in the case against AEG, which their grandmother and primary caretaker filed in August 2010.
Prince spoke softly as he began testifying, and the first exhibit shown to jurors was a photo taken with his grandmother on his and Paris' first day of school.
He described his school life, including taking a summer course in U.S. history, participating on the school robotics team and volunteer work.
Another image showed Michael Jackson playing piano with his son while Prince was still a toddler.
Plaintiffs' attorney Brian Panish asked Prince whether he was interested in pursuing a career in music.
"I can never play an instrument and I definitely cannot sing," Prince said to laughter from the jury.
He said he wanted to study film or business when he goes to college.
The trial is expected to last several more weeks.
Anthony McCartney can be reached at http://twitter.com/mccartneyAP .