When he stepped onto a court on Sunday night (Monday AEDT) to play alongside his son, Bronny, for the Los Angeles Lakers, this moment was more than basketball history to him.

It was the realisation of a family dream.

LeBron and Bronny became the first father and son to play in any NBA game together during the first half of the Lakers ' preseason contest against Phoenix, playing just over four minutes side-by-side in the second quarter.

"It's pretty cool for the both of us and especially for our family," LeBron said. "It's definitely a moment that I will never forget."

The James family's remarkable moment coincidentally happened on Bronny's 20th birthday, and it felt like a celebration for the 39-year-old LeBron, who has spoken about his desire for this opportunity since his son was in high school.

"For a father, it means everything," LeBron said.

"For someone who didn't have that growing up, to be able to have that influence on your kids and have that influence on your son, be able to have moments with your son - and the ultimate, to be able to work with your son - that's one of the greatest things that a father could ever hope for or wish for."

Bronny was told by coach JJ Redick before the game that he would be playing alongside LeBron, but the rookie maintained his usual cool demeanour both before and after the moment.

"I was pretty psyched for that," Bronny said.