Dominic Breazeale suffered a brutal first-round knockout at the hands of heavyweight champion Deontay Wilder on Saturday but felt the referee stopped the fight too early.
WBC title-holder Wilder sent Breazeale to the canvas with a ferocious right hand to retain his belt after just 137 seconds at Barclays Center, improving to 41-0-1 in the process.
The mandatory challenger was almost back on his feet by the time referee Harvey Dock completed his 10 count, though he appeared in no condition to continue.
It was just the second defeat of Breazeale's career, the American having lost to Anthony Joshua in the Briton's first world title defence in June 2016, but he felt he had more to give.
"I think the ref stopped it a little early because I could hear him saying 'seven' and 'eight', but that's boxing," said Breazeale.
"He did his job and kept us safe for our next fight. I got on my feet and had my legs under me. It's the heavyweight division so there's going to big shots from guys with power.
"This was a situation where he landed the big right hand before I did. I thought I was going to come on in the later rounds. I'll be back and go for the heavyweight title again."
After registering the 40th knockout of his career Wilder said a unification bout with IBF, WBA and WBO champion Joshua will happen, although rematches against Tyson Fury or Luis Ortiz could also be up next.