WBC, IBF, WBA welterweight champion Errol Spence is very confident ahead of Saturday's undisputed fight with WBO champion Terence Crawford.

The fight will headline a Showtime PPV card at the T-Mobile Arena in Las Vegas.

Their fight took a long time to put together, with plenty of twists and turns, but a deal was finally struck earlier this year.

“I wasn’t close at all to giving up at all,” says Spence to Sports Illustrated. “Even my handlers was telling me to either move up or move on. It’s too hard of negotiation. But I stuck to the negotiation. I said, ‘No, we can make this fight happen.’ Eventually it happened. It definitely took a while, but it happened now, and I feel like this fight is the biggest fight, not only in a decade but probably the last 20 years.”

Spence had a solid offer on the table to face Keith Thurman at 154-pounds, but he decided to stick around at welterweight to face Crawford.

He couldn't see a scenario where a jump in weight would make sense without facing Crawford first.

"Because it’s more about this being a legacy-defining fight. This is just a great fight period. And I feel like I would’ve had [Crawford’s] name over my head if I would’ve moved up. Everybody would’ve still put my name with his name and the same thing with him. They would’ve put my name with his name. I feel like just to all the naysayers that are saying different things, they were saying he going to beat me and saying that he’s a better fighter than me. I’d rather put that to rest come July 29th on Showtime pay-per-view. I’m willing to put everything on the line, do everything it takes to win this fight. Everybody’s got to make sure they tune in. It’s going to be one for the books," Spence said.