The HBO Guide for July of 1982 has the Hagler vs. Hearns fight listed at 9 pm, but it never occurred. Thomas Hearns initially dropped out and was replaced by Fulgencio Obelmejias, but then that was cancelled due to an injury from Hagler and rescheduled for Oct. 30th. This happened after the guides were set to print, so trying to figure out what HBO actually aired that night is a bit of a mystery due to conflicting sources.
This notice was found on newspapers.com by a member of the Vintage HBO Guides! group on Facebook:
But I also found this TV Guide Listing on archive.org that shows something different:
And yet another account comes from this listings in the N.Y. Times:
What really aired? Perhaps the answer is on a betamax cassette, forgotten in a box in someone's attic?