Naoya Inoue remained undefeated after retaining the undisputed junior featherweight title with an eighth-round technical knockout of Ramon Cardenas in front of a packed house inside T-Mobile Arena.

,who was knocked down in the second round, played the aggressor much of the fight by using precision and power to carve his way through Cardenas (26-2), frequently sending the announced 8,474 gathering into a frenzy.

“By watching tonight’s fight, everyone is well aware that I like to brawl,” Inoue said. “I was very surprised (at the knockdown), but I took things calmly and put myself together. … From then on, I made sure to not take that punch again.”

The Japanese icon, affectionately known as “Monster,” landed 57 of 103 power punches (55%) in the sixth and seventh rounds alone, per CompuBox.

Inoue, fighting in Las Vegas for the first time in four years, was ahead by identical scores of 68-63 on all three judges’ scorecards at the time of stoppage.

“The fans here were supportive and great,” said Ionue, 32. “And I hope I was able to entertain them.”

Inoue opened the fight with confidence by landing several shots.

But in charging forward in the second round, Inoue walked directly into Cardenas’ right-handed counter, dropping the undefeated champion.

It wouldn’t take long for Inoue to shake off the miscue, as he continued to dominate by picking his spots, going from the body to the head, wearing down his challenger. By the end of the fourth round, Inoue had landed 48 of the 90 punches thrown, including 33 power shots.

Cardenas, though, appeared to absorb everything, while countering when he could.

Inoue caught Cardenas near the halfway point of the sixth round and drove him into the corner while landing several combos. With Cardenas throwing counters, Ionue used the final 18 seconds to pulverize the 29-year-old challenger.

Inoue scored his first knockdown of the fight in the seventh round, catching Cardenas in the corner and dropping him after landing four consecutive rights.

Knowing he had his opponent defeated, Inoue was relentless in the eighth round, eventually prompting referee Thomas Taylor to step in.

“He’s pound-for-pound one of the greatest fighters on the planet,” Cardenas said.

Inoue is scheduled to fight a mandatory bout against Murodjon Akhmadaliev in September, in what could be his toughest challenge to date.

The co-main event saw Mexico’s Rafael Espinoza (27-0, 23 KOs) retain his WBO featherweight belt with a TKO of Edward Vazquez (17-3) at 1:47 of the seventh round. Espinoza dominated in all seven rounds, pouring it on with a bevy of punches from the fourth round until referee Harvey Dock stepped in to stop the fight.

Rohan Polanco dropped Fabian Maidana with a thunderous body shot in the 10th round and went on to win by unanimous decision. With the win, Polanco (16-0, 10 KOs) retained his minor welterweight title. Maidana fell to 24-4.

Emiliano Vargas (14-0, 12 KOs) used a vicious combination that finished with a left uppercut to the face of Juan Leon (11-3-1) for a second-round technical knockout at 1:40. Vargas is the son of former two-time light middleweight champion, Fernando Vargas.