Mike Tyson -- We Should Celebrate Joe Frazier

Mike Tyson has issued a statement about the death of boxing icon Joe Frazier -- calling Joe's passing a "sad day" ... but saying we should "honor him by celebrating his accomplishments."

Tyson went to Twitter ... and wrote, "Frazier and Ali were quintessential, the apex of pedigree fighting in which each man would not give an inch until they were dead. Their era was competitive fighting at the highest level."