Celebs and retired fight stars beating the hell out of each other in boxing matches is GOOD for the sport ... so says Nigel Lythgoe, who claims the spectacles are reviving interest in the sweet science in a big way.
The former "American Idol" producer broke it all down for Harvey and Charlie on "TMZ Live" on Tuesday ... explaining the Jake Pauls and the Bryce Halls of the world are breathing life into a sport that he says was struggling.
"[Boxing] needed something," Lythgoe said.