Liston came back to his corner after Round 2 with a nearly closed right eye.
The cornermen were waiting for him with an ice-pack, and hurriedly applied it to the closing right eye in an effort to stop the swelling that was becoming more serious looking by the second.
As the bell sounded for Round 3, Sonny was slow getting out of his corner, and was met by an aggressive Valdes, who came at him quickly from across the ring.
In a flash Nino fired a 3-punch volley followed by a stunning left hook that crashed off of Liston's exposed jaw.
Stunned and angered, Liston retaliated with a volley of solid punches that seemed to take everything out of the 34 year-old Nino's legs, as he rocked back on his heels.
Liston then crashed a big left hook on Ninos' jaw.
With a stunned Nino in front of him Sonny fired a solid combination that drove Nino into the ropes where he bounced off into a savage right cross that dropped Nino like a weight.
Valdes, with his right arm dangling over the lower rope strand was on his knees until the count reached 7 then rolled onto the canvas to be counted out at 0:47 of the round.