LAS VEGAS — After Floyd Mayweather’s snoozefest decision over Manny Pacquiao in 2015, the outcry was swift and harsh.

The superfight shattered revenue records, and the largest driver of profits was the 4.6 million pay-per-view buys in the United States at $99.99 to view the welterweight title bout in high-definition.

With tens of millions of eyeballs squarely fixated on the boxing world for one night — many for perhaps the first and final time — a sour taste was left in a lot of mouths. Some casual sports fans resorted to the tired old axiom that “boxing is dead.”

Of course, it isn’t, but this go around, with another opportunity to showcase the sport to millions of new fans, Mayweather must deliver.

Not just a victory — that much is expected in such a mismatch: a fight against Conor McGregor, a mixed martial artist making his pro boxing debut. No, Mayweather needs to do much more than just win. He must do so in exciting fashion inside the distance to save the sport from surefire criticism that would follow another dreadful event.

Mayweather vowed Tuesday shortly after his grand arrival to do just that Saturday and finish McGregor inside the distance of an exciting fight. Such a performance wouldn’t just boost Mayweather’s sizable ego; it would also boost his business interests as owner of his eponymous promotional company.

For if Mayweather is to carry McGregor for 12 boring rounds, much like “Money” did in his previous farewell fight against Andre Berto, the backlash will be devastating to the sport. Casual sports fans surely will opine that the bout would have been entertaining, if only it were held in the confines of a UFC octagon.

They’ll vow to never watch boxing again. Who could blame them?

Photo by Esther Lin / Vox Media

The September 16 superfight to decide middleweight supremacy between Canelo Alvarez and Gennady Golovkin would surely feel the effects of yet another boring Mayweather fight. After all, it’s hard to imagine first-time boxing viewers shelling out hard-earned cash to watch Canelo-GGG to mix it up if they witness Mayweather and McGregor stink it out.

But Floyd insisted Tuesday that it won’t come to that.

“I’m a human being. I’m not gonna do it for anyone. I’m doing it for myself, but I wanna entertain everybody; I wanna give everybody a good show,” said Mayweather, clad in a black hat with a red-and-black plaid shirt. “After the Pacquiao fight, I feel like everybody deserves excitement — a lot more excitement. Even with the Pacquiao fight, no matter what way any situation go, they always point the finger at me. This was a guy that threw 1,000 punches (in many previous bouts), and (was named) fighter of the decade.

“From the beginning, with the Pacquiao fight, if you go back and look at the first round, first shot I hit him with to let him know: It’s not what you think it is, you’re not just going to run up in there. Then he felt the strength and it was totally different.”

It will be a different fight once Conor feels the power, too, Floyd insisted. But unlike Pacquiao, an elite boxer conditioned to fight 12 rounds, McGregor is sure to gas early in the fight. Nothing tires out a fighter quicker than wildly overextending and missing with punches.

And once McGregor’s tank is empty, Mayweather should really be able to land at will. If he’s serious about his quest to entertain the masses and score the knockout, it will come. But regardless of the outcome, Mayweather isn’t worried about the sport that brought him unimaginable riches.

“Nothing is a threat,” the 40-year-old said. “Boxing is legendary and boxing is here to stay. … I do wanna go out there and get it in from the opening bell. He’s going to come out like (Marcos) Maidana. I dealt with that before so I know how it is. If he come out that like that, can he keep that same endurance for 12 rounds if he plans on going the distance? We’ll see what he got.”

Photo by Esther Lin / Vox Media

And what does McGregor have? Surely not much in the way of boxing ability. The workout videos tell it all. McGregor insisted Tuesday that following a full, eight-week training camp, he’s a far better boxer than he once was. But this isn’t sparring with Paulie Malignaggi. He’ll be face-to-face with an all-time great.

“When he gets hit he’s going to find out that this is totally different,” Mayweather promised. “The brittle hands? Let him keep saying all that. When I come across his head, he’s going to find out what it really is. Believe me.

” … This fight is not going the distance, I’m telling you.”

Just imagine what a boon to boxing it would be if, on the largest stage imaginable, Mayweather scores a knockout of the UFC’s biggest star that plays on SportsCenter over and over. A video that goes viral on social media.

It wouldn’t truly prove boxing is better than MMA, of course, but many casual fans are making this fight exactly that: boxing vs. MMA.

For that reason alone, the sport of boxing better hope Floyd is telling the truth.

Mike Coppinger is the Senior Writer for RingTV.com. Follow him on Twitter: @MikeCoppinger

Photos by Ester Lin / Vox Media