LAS VEGAS – Kenneth Sims Jr. has been an undeniable force while reeling off eight consecutive victories, and all the reasons for that streak were on display Saturday in his TKO of replacement foe and former world titleholder Jonathan Romero.

After a 15-month layoff connected to a promotional change, Sims let loose with a crushing barrage with Romero backed to a neutral corner in the fifth round, causing Romero to briefly slump forward.

While Romero recovered well enough to finish the round, his corner informed referee Robert Hoyle that the damage was done and Hoyle stopped the fight.

“I felt like I was making my professional debut again,” Sims said. “It was great to be in the ring again after so long. Sparring is sparring, and to be inside a real fight was something I was really happy about, and I felt great in being able to get my groove back and catch my distance with my gloves laced up again.”

Afterward, junior welterweight Sims (21-2-1, 8 KOs) called out his new fellow Golden Boy Promotions fighters who will be fighting in the fall, Arnold Barboza Jr. and former champion Jose Ramirez, insisting that he feels prepared for a title fight.

“I’ll be watching,” Sims said.

Nothing that happened Saturday should discourage such high hopes.

Chicago’s Sims felt Romero’s power early, then immediately responded with rapid body shots delivered with both hands. A hard power left to the torso froze Romero on the ropes.

Sims battered Romero (35-5) on the ropes of a neutral corner in the third, driving hard blows to the head and body, but Romero showed his mettle by answering back, only to spend the final seconds absorbing another pounding.

Romero again impressively retaliated off the ropes in the fourth, prompting Sims to back up and clear his head until he recovered enough to deliver more combinations.

Colombia’s Romero was summoned on Thursday to replace Jair Valtierra (17-3), a Mexican fighter who had travel document problems and couldn’t reach the U.S. in time.

Romero, 37, was the IBF junior featherweight (122 pounds) titleholder in 2013 before losing the belt to Kiko Martinez one fight after he won the strap.

Recently, he has spent his time as a gatekeeper, losing three consecutive fights. Romero has been knocked out in three rounds by junior lightweight Abraham Nova (23-3, 16 KOs), knocked out in the first by junior lightweight Albert Bell (26-0, 9 KOs) and outpointed by Manuel Jaimes (16-1, 11 KOs) since July 2023.

The Jaimes fight took place July 13.

Because Romero didn’t arrive until Friday evening, Sims had to wait for the weigh-in, and ended up enjoying a meal, weighing in at 148.4 pounds even though he was first in line among 22 fighters for the Friday morning weigh-in and was under 140 pounds at that time.