which boxers had the best careers after 1st round ko loss ?

Greetings ed! Growing up with Floyd, I saw his 'inner demons' so to speak. From your comments, you're probably not the biggest Patterson fan.
Eddie had his personal demons as well but was very viable going into the Sweden fight with Floyd and got his ass kicked.
The Chuvalo fight was Ring Magazine's Fight of the Year! Floyd took major shots to the head, stayed upright, and simply outworked George in a clear decision.
Styles make fights and Floyd's brutal dismantling of Henry was something that Ali could never pull off.
Ali 1? There was the bad back thing there and the small Floyd could never beat Ali but he hung in there.
Quarry? Patterson, as I'm sure you know, never let us see his best given his nature and his passivity. Granted, Jerry hadn't quite reached prime yet but, despite the huge Quarry 2nd round, if Floyd hadn't went "cigar store Indian" in the 9th and 10th, he had an easy decision for lunch!
Quarry 2? Same Floyd, but without his "I don't want to hurt anyone demeanor" he had Jerry a second time.
Ellis? That one's been tossed around for decades! I'll admit again Patterson's passivity cost him in that one but I've got a picture of the ring shot when Ellis got the decision, a passive Floyd, unmarked, and a still champion Ellis with a broken nose, both eyes closing, broken nose, his face a bloody, pulpy mess!
Bonavena? Oscar NEVER had an early big lead in that fight. Floyd hung, counterpunched effectively, and IMO copped a close decision.
His last fight? Ali? Again, he could never beat Ali but can you deny his great effort in that one? Winning rounds at almost 38 yrs. old. For the record that eye that Ali closed was a residual effect from Devil Green's cheap head butt that damaged Patterson's eye in his Sept. 70 initial comeback.
Ease up on Floyd, a HOF ATG.

 

Kudos to Kalambay who managed to stay world class post Nunn.

And Patterson deserves mention for coming back from the two ego destroying one round defeats to the Ugly Bear.

 

Amir Khan