How things changed for Kirkman after that brutal beating. Later he was used as one of the "opponents" for Foreman during the circus against five men. Kirkman showed that he was not a joke as he went 3 rounds with a tired Foreman, redemption (in his own mind) for his earlier loss to the man. Personally I think Foreman's late round stoppage win over Peralta is one of his more impressive pre-title wins. Never seen any film of it to decide whether it was an impressive performance though. Peralta was a former light heavy, but proved a difficult man to stop for many heavyweights.
And that Chuvalo hammering. Very very brutal and look at all the fight experience George had going into the fight. There were picking him to win. Another unheralded fight was the Wepner bout. That was another case of giving up a ton of experience against a tough guy and it was George's 3rd fight. The big thing was Foreman usually fought as an undercard guy on the Frazier championship fights. The rest of his fights were in small towns and he was just keeping busy. Most managers would not have their guy even bothering with those cheap dollar fights and would be concerned about a cut or loss or something. Foreman's weight was lower back then and after that Ali loss, he went up in weight and was not as effective with that lighter workload.