Champions who lost their title via KO, but won the re-match to take back the title.

Floyd Patterson.

 

Rocky Graziano, Tony Zale

 

Roy Jones Jr. Although it was a disqualification not a KO.

 

Klitschko doesn't count. He was already the champion when he beat Brewster in the rematch.

 

Graziano never regained the title he lost to Zale.

 

I thought all three fights were title fights, but I see that only the last two were. I stand corrected.

 

All three were championship fights.

Zale as champ defeated Rocky, then lost the title to Graziano, before regaining it.

I think what you may be confusing is that Zale got his ass kicked in fight one, but won, totally dominated the rematch, but lost.

 

Terry Norris, getting knocked out by Simon Brown and then winning a UD in the rematch.

 

Emile Griffith was in some 3 fight series with Paret, Rodriquez, and Nino Benev. where he lost and regained the title.

 

None of Emile Griffith´s were by k.o.

Woller

 

He also wasnt really a legit champ when he was ko'd

Joe Louis comes to mind, although he wasnt a champ at the time either and didnt become a champ by beating Schmelling either

Charles should have got the third fight with Walcott and regained the championship after losing the title by KO

 

I misread the thread...none by k.o.

 

Koichi Wajima, Pone Kingpetch, and Sam Serrano come to mind.

 

Vazquez against Marquez. The first fight was TKO retirement win for Marquez, only to be stopped on his feet during the rematch.