From the moment the fight was announced, Errol Spence has openly promised that he will become the first to knock out Shawn Porter.

Nothing in the past several weeks of training camp has him any less convinced of such an outcome for their Sept. 28 Fox Sports Pay-Per-View headliner. In fact, he’ll consider it a disappointment if it doesn’t happen.

“A little bit; it will be a little bit of a letdown,” Spence (25-0, 21KOs) admitted on the thought of the fight going the distance, during a special Sunday afternoon edition of Inside PBC (Premier Boxing Champions) Boxing live on Fox to promote their welterweight title unification bout at Staples Center in Los Angeles, Calif. “It’s something that I really want. I want to be the first person to stop Shawn Porter. He wants to be the first to stop me too. I think it’s in the back of both our minds.

“I’m not gonna go out of my way or look sloppy or try something extra just to get the knockout, you know. If it happens, it happens. But hopefully, I get it on Saturday night.”

It’s a bold prediction given Porter (30-2-1, 17KOs) has only been down once before through 33 pro fights, a 12th round knockdown at the hands of Adrien Broner in an eventual June 2015 points win in Las Vegas. Ohio’s Porter boasts a stellar résumé, especially considering the depth of the welterweight division which—along with his aggressive fighting style—makes it all the more remarkable that the two-time and reigning welterweight titlist hasn’t been off his feet more often.

Spence’s insistence of an early night has been additionally met with skepticism, given his last outing.

The unbeaten southpaw from Desoto, Texas went 12-rounds with previously unbeaten Mikey Garcia, now a former four-division titlist who’d never fought above 140 and was coming up from lightweight for their title fight this past March. Spence won every round with relative ease but at no point in their PPV main event came close to taking it out of the hands of the three ringside judges, even in pitching a shutout across the board.

It’s also worth noting that the bout was the first time in nearly five years that Spence was forced to go to the scorecards. His title reign began with a knockout, stopping England’s Kell Brook in the 11th round of their thriller on the road in Sheffield, England. His first two title defenses also ended inside the distance, stopping former two-division titlist Lamont Peterson in seven rounds last January and needing just one round to rid himself of previously unbeaten Carlos Ocampo last June.

All three are naturally bigger than Garcia, who simply had a better strategy for hearing the final bell, one that he doesn’t believe exists in his next fight.

“I think Mikey is more defensively responsible than Shawn Porter,” explains Spence. “I feel like with Shawn’s style, it definitely enables me to catch him coming in and knock him out.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox