Musk will have to go to trial to defend himself for mocking Unsworth as a pedophile in a verbal sparring match that unfolded last summer after the underwater rescue of youth soccer players trapped in a Thailand cave.
Musk called Unsworth a "pedo" in a July 15, 2018, post on this Twitter account after Unsworth, in an interview with CNN, dismissed Musk's attempts to help rescue the soccer players as a "PR stunt." Unsworth also derided the submarine that Musk had built for a rescue mission, prompting Musk to lash back on this Twitter account, which had 22.5 million followers at the time.
The jury trial in the suit will begin Dec. 3.
Unsworth is seeking more than $75,000 in damages from Musk, a multibillionaire. The suit also seeks a court order prohibiting Musk from making any further disparaging comments.
The pretrial hearing comes after a bad week for Musk, who unveiled the Tesla Cybertruck on Thursday and had to laugh off a failed demonstration when the vehicle's armored glass windows shattered instead of withstanding blows from metal balls.
The Associated Press contributed to this report.