Terence Crawford is the new undisputed welterweight champion after defeating Errol Spence Jr. handily at T-Mobile Arena in Las Vegas on Saturday night.

It was a “tour de force performance” for Crawford, who scored a ninth-round TKO after having his way with Spence all night. That included knocking his opponent to the floor in Round 2 and twice in Round 7 to win the IBF, WBA and WBC 147-pound titles along with the WBO belt, per ESPN's Mike Coppinger.

Referee Harvey Dock ended the fight at 2 minutes, 32 seconds into Round 9, after Crawford was again laying a beatdown on Spence.

“Like I said before, I only dreamed of being a world champion,” Crawford said after the fight. “I'm an overachiever. Nobody believed in me when I was coming up, but I made everybody a believer.”

ESPN's No. 1 pound-for-pound boxer, the 35-year-old improved to 40-0 with 31 KOs and became the first man to capture all four belts at 147 pounds, per Coppinger.

“It means everything because of who I took the belts from,” Crawford explained. “I'm so mixed with so many emotions I can cry right now.”

In one of the greatest walkouts in boxing history, Crawford was accompanied by Eminem himself, with the classic “Lose Yourself” playing as he entered the ring. It was tough to think he wasn't going to win with Marshall Mathers in his corner.

“Crawford was in total control of the bout beginning with Round 2, when Spence was floored for the first time in his career,” wrote Coppinger on Saturday night. “Crawford used a left hand to Spence's body that set up a southpaw jab for a flash knockdown.”

Spence, who is 28-1 himself with 22 KOs, admitted that he was not the better fighter in Las Vegas on Saturday.

“He was the better man tonight,” ESPN's No. 2 welterweight and No. 4 pound-for-pound boxer said after the fight. “He was using his jab, and my timing was a little bit off. He was catching me in between shots. I make no excuses.”

Although it was billed as a meeting of elite boxers, it was Terence Crawford who seemed miles ahead of Errol Spence Jr. on this occasion.