"On the night of the fight when I started to warm up, man I felt good," the undefeated Fa, who now has a 13-0 record, said. "It just seemed like I had a bit more snap in my punches.
"I took advantage of it and made him feel my power and I could tell he didn't really like it.
"I was like a savage that night. The ref was screaming out 'stop', but I didn't want to stop. That could have been the first time I've had that feeling towards a person. I didn't treat it personal but I knew it was a very, very important fight for me, so I walked into the ring with a real killer mentality."
The delight shown by his American promoter Lou DiBella once the fight was called off was an indication of how important it was in Fa's development. The 28-year-old wants to improve his ranking with the WBO and soon could be in a position to challenge fellow Kiwi Joseph Parker should the WBO world champion remain undefeated.
"It was the first fight that's been televised in the States," Fa said of its significance. "It could lead to a TV contract there - it means more publicity for me and more cash for me and my family. It was a very important fight. I think Lou was very stoked about my fight and also how his fighter fought the weekend before - Deontay Wilder - who finished his show in a similar fashion [a devastating knockout of Bermane Stiverne].
"The past two fights I had before this one gave me a kick up the behind to basically take this more seriously."
Fa has returned to training and will definitely fight in the United States again before February 25 next year. It will be the last of a current three-fight deal to fight there.