Lovitz and Dick, one-time "NewsRadio" co-stars, ran into each other at the Laugh Factory last week. Lovitz was angry about what he perceived was a tasteless joke Dick made last year, in which the comedian put "the Phil Hartman hex" on Lovitz, referring to the murder of the "Saturday Night Live" and "NewsRadio" star by his wife, who subsequently killed herself, E! News reported.
Lovitz asked for but didn't receive an apology, witnesses said.
"Jon lost his temper and took Andy's head by the hair and smashed it a couple of times on the bar in the lobby," Laugh Factory owner Jamie Masada told E! Online Tuesday.
Lovitz and Hartman were close friends.
Of the earlier incident, Lovitz said Dick "looked at me and said, 'I put the Phil Hartman hex' on you -- you're the next one to die.'"
Masada said Dick's personality and routines can be off-putting to his peers, but "hopefully this is a start for him to wake up."
Dick did not comment on the incident.