Who gave Ali his toughest fight before the 3 year ban, I feel Chavalo landed on him more than anybody else at that stage of his career, but who came closest to beating him in the 60`s?
Jones, Cooper and Chuvalo all gave him rough moments - though to be fair, the first two fought him when he had less than 20 fights and was in his early 20’s. George Chuvalo fought a fully matured Muhammad Ali who had the experience of being a world champion.
Henry Cooper gave him a rough time, a great boxer he was - just cut easily. He had a hard time against Doug Jones, back when he was still Cassius Clay and his style wasn't fully developed yet. Sonny Banks was the first person to KD Ali. It's said that Ali's earliest fights (though most footage has been lost or damaged on his first 12 fights or so) were so easy they looked like exhibitions. In his prime 64-67, no one gave him trouble for more than a few seconds in a round it felt like. He whooped Williams, Terrell, Liston, and Zora Folley.... Speaking of his Zora Folley fight, I think there is a greater chance his fight with Ali was staged than Ali's rematch with Liston. I do not think Folley was as hurt as he was appearing, rolling around in the ring trying to stand... suspicious. Ali definitely hit liston with that "phantom punch", Liston did however stay down on purpose due to lack of heart. I like Ali, my favorite fighter.
I would have to go with George Chuvalo when they fought on March 29 1966, in Toronto, Canada. Ali abandoned his usual movement in some of the rounds by allowing The Washer Woman to pound his midsection, as Ali was boasting that he could take Chuvalo's best and be the first to kayo him. Ali won by unanimous decision to retain his title. Henry Cooper did not give him a rough time in their title bout rematch on May 21 1966, Henry was stopped on cuts that required 14 stitches, in round 6, no knockdown this time. Karl Mildenberger gave Ali problems on Sept 10 1966, in Frankfurt, Germany, because of his awkward southpaw stance, Muhammad scored three knockdowns during the bout, before stopping Karl in the twelfth round. The final three defenses, Cleveland Big Cat Williams, Ernie Terrell, and Zora Folley did not give Ali any problems.