ARLINGTON, Texas — Terence Crawford went to Scotland to win the WBO lightweight title, then defended it twice in his Nebraska hometown.

Now the undefeated Crawford is moving up to the next class, and in his first fight of 2015 takes on Thomas Dulorme for the vacant WBO junior welterweight title Saturday night.

"I feel like I need to use my momentum to my advantage and I feel like I've got the momentum right now," Crawford said. "I don't want to take any steps backward. I want to stay moving up."

The bout is scheduled for 12 rounds on the University of Texas-Arlington campus. The fight comes a week before Crawford, 25-0 with 17 knockouts, will be in New York to accept his 2014 fighter of the year award from the Boxing Writers Association of America.

Right after his second lightweight title defense in Omaha, a unanimous decision over top-ranked contender Ray Beltran last November, Crawford said he was done at 135 pounds and was moving up to the 140-pound class.

"My body is growing. I'm filling out a little more," the 27-year-old Crawford said this week. "I just feel like that was the right time to move up before I started having real serious problems because I struggled hard to make that weight in that fight."

Crawford's promoter is Bob Arum, who is in North Texas for the bout that comes only two weeks before the long-awaited fight in Las Vegas between another of his boxers, Manny Pacquiao, and Floyd Mayweather Jr.

Arum was quick to point out that Pacquiao-Mayweather is at the 147-pound welterweight class, which would seem a natural progression for Crawford.

"He's pretty well cleaned out the lightweight division," Arum said. "Big, big step in his career as he steps up. This is a very, very crucial first step for Terence to join that really truly elite group of fighters.

"We believe Terence is the emerging, rising, superstar in boxing so that when Floyd and Manny shortly, pretty shortly, hang up their gloves, they'll be missed," he said. "But not as much because there will be this new superstar on horizon in Terence Crawford."

Crawford insisted multiple times that his only focus is on his first junior welterweight match.

HBO will televise Saturday night's fight, and a short documentary broadcast on the network in advance this week showed Crawford's struggle to lose more than 5 pounds in the seven hours leading up to the weigh-in before the Beltran fight to get to 135 pounds.

This time, Crawford said he has been at weight for more than a week and weighed in Friday at 139.8 pounds. Dulorme, the 25-year-old Puerto Rican who is 22-1 with 14 knockouts, was at 139.2 pounds.

Crawford is an overwhelming favorite over the hard-punching Dulorme, who in December scored 10-round split decision over Hank Lundy.

"I am not surprised by the odds because everyone thinks this is a very comfortable fight for Crawford." Dulorme said through an interpreter. "I will say this, those who bet with me as the winner of the fight are going to take home a nice chunk of money."

To win the WBO lightweight title, Crawford went to Scotland in March 2014 to fight defending champ Ricky Burns on his home turf. Three months later, in his hometown, Crawford won his first title defense with a ninth-round TKO against former champion Yuriorkis Gamboa, the Cuban Olympic gold medalist.

Dulorme has won his last six bouts since being knocked out in a welterweight fight by Luis Carlos Abregu. Dulorme started the shift back to the junior welterweight division after that October 2012 loss.

"My professional boxing career has been uprising comfortably," Dulorme said. "I'm very happy and I'm very positive about this next step with a win over Crawford."