LAS VEGAS – Diego Pacheco passed perhaps the most threatening test of his blossoming career Saturday night.

The emerging super middleweight contender didn’t dominate previously unbeaten Steven Nelson the way he had hoped. He did more than enough, however, to unanimously out-point a comparatively inactive Nelson in their 12-round main event at The Cosmopolitan of Las Vegas.

Nelson never stopped trying. He just had trouble getting inside and landing clean punches on the 6-foot-4 Pacheco, who stands six inches taller and is 13 years younger than the Omaha, Nebraska native.

Pacheco’s overhand right and right uppercut were consistent weapons, too, during the second half of a fight DAZN streamed.

Judges Tim Cheatham, Max De Luca and David Sutherland scored their fight identically, 117-111 for Pacheco. Each judge scored nine rounds for Los Angeles’ Pacheco.

“I felt good, man,” Pacheco told DAZN’s Chris Mannix. “Steven Nelson is a great fighter. It wasn’t my best performance, but we did what we had to do to get the win.”

Pacheco, 23, improved to 23-0. The Ring’s No. 3-ranked super middleweight contender commended Nelson’s chin, which prevented Pacheco from producing what would’ve been his 19th knockout.

The 36-year-old Nelson (20-1, 16 KOs), Terence Crawford’s close friend, fought for just the fifth time in the five years since he stopped the late Cem Kilic (then 14-0) in the eighth round of their January 2020 bout at Hard Rock Hotel & Casino in Atlantic City.

Nelson nailed Pacheco with a left hook in the 12th round. Pacheco stood his ground and fought back, only to have Nelson land a hard right hand later in the 12th round.

Pacheco cracked Nelson with a right hand that rocked him in the 10th round. Nelson recovered quickly and avoided taking a comparable damaging punch for the rest of the 10th round.

There weren’t many flush punches landed in the sixth round, but Nelson and Pacheco exchanged punches in the opening minute of the seventh round. Pacheco connected with the more damaging punches during that round, including several vicious right uppercuts that Nelson absorbed without taking a backward step.

Pacheco caught Nelson with an overhand right and then slightly with a right uppercut toward the end of the fifth round.

A right hand by Pacheco cut Nelson over his left eye during the fourth round. Nelson wasn’t hurt by that shot, but it was the flushest punch Pacheco landed to that point.

Pacheco kept his distance in the third round, but he didn’t throw many punches as he moved away from Nelson.

Pacheco connected with an overhand right toward the end of the second round. Nelson quickly fired back with a right hand that backed Pacheco into the ropes.

Nelson pushed the action during the opening round, but neither fighter landed a consequential punch during the opening three minutes.