Rank Muhammad Ali's Challengers - 1st Reign

Joe Frazier stopped Buster Mathis in 11 rounds on March 4 1968 to win the New York State World Heavyweight Title plus 4 more states, while Jimmy Ellis won the WBA title with a split decision over Jerry Quarry on April 27 1968. You are correct, Joe did not enter the WBA Tournament, he was upset at not being able to fight Muhammad Ali in 1967, but his management did not want that fight, as Ali was in danger of being imprisoned for his conviction of Draft Evasion, also Ali's license was revoked, his title stripped from him.

 

From what I read, Joe would have had to fight either Karl Mildenberger or Ernie Terrell.

 

Karl Mildenberger was favored to win the tournament, based on his tough performance against Muhammad Ali on Sept 10 1966, but Oscar Bonavena took care of him.

 

Thad Spencer defeated Ernie Terrell rather easy, knocked him down, won on points. Jerry Quarry stopped Spencer on Feb 3 1968, TKO 12. Leotis Martin was stopped by Jimmy Ellis in 1967, TKO 9.