UNCASVILLE, Connecticut – Jaron Ennis delivered the punishing performance he promised Saturday night against Sergey Lipinets.

The flashy, undefeated Philadelphia native picked apart the former 140-pound champion before taking him out in the sixth round of their 12-round welterweight fight at Mohegan Sun Arena. Ennis knocked Lipinets flat on his back with a right-left combination that emphatically ended the main event of Showtime’s tripleheader.

Referee Arthur Mercante Jr. immediately stopped the action at 2:11 of the sixth round once Lipinets hit the canvas.

The 23-year-old Ennis (27-0, 25 KOs, 1 NC), who was listed as a 12-1 favorite, became the first opponent to knock out Kazakhstan’s Lipinets (16-2-1, 12 KOs). Lipinets was the most accomplished opponent of Ennis’ five-year pro career, but the fast-handed, intelligent, multidimensional contender tore through the ex-IBF junior welterweight champion pretty easily.

“It wasn’t my hardest fight,” Ennis said during a post-fight press conference. “I was in there, you know, doing what I wanted to do. I don’t take nothing away from Sergey Lipinets. He a great fighter, but I was just in there having fun, doing me, you know, being real relaxed and putting on a show.”

Lipinets, 32, had previously lost only to Mike Garcia, who won a unanimous decision against Lipinets in March 2018. Garcia (40-1, 30 KOs) dropped Lipinets in the seventh round of that 12-round fight and won the IBF junior welterweight title from him three years ago at Freeman Coliseum in San Antonio.

His loss to Ennis marked a second straight setback for Lipinets. He settled for a majority draw with Canada’s Custio Clayton (18-0-1, 12 KOs) in previous appearance, a 12-round fight for the IBF interim welterweight title October 24 at Mohegan Sun Arena.

Ennis essentially hit Lipinets at will, but he refrained from getting carried away with trying to knock out Lipinets earlier in their fight.

“He been in there with the best,” Ennis said. “You know, he fought Mikey Garcia, Lamont [Peterson] and they couldn’t stop him. And I did. But I knew he was gonna be durable. That’s why I really didn’t jump on the gas like how I wanted to. I just coasted out, I took my time and broke him down.”

Ennis, who still hasn’t boxed beyond the sixth round, landed an unusually high 53 percent of his power punches, according to CompuBox’s unofficial statistics. CompuBox counted 91-of-172 power punches and 125-of-300 punches overall for Ennis.

An aggressive, relentless Ennis pummeled Lipinets with an array of power punches before blasting him with the combination that instantly ended their fight in the sixth round.

Ennis was battering Lipinets against the ropes when Lipinets landed a low right hand that caused a brief break in the action with about 1:20 to go in the fifth round. Mercante warned Lipinets for what he ruled an unintentional foul.

Mercante credited Ennis with a knockdown with 1:35 to go in the fourth round, but Lipinets appeared to trip on Ennis’ foot as Ennis threw a left uppercut that missed. Nevertheless, that counted as the second trip to the canvas in Lipinets’ career.

A round after starting in a southpaw stance, Ennis began the third round in an orthodox stance. Ennis blasted Lipinets with a right uppercut early in the third round.

Lipinets landed a right hand in the middle minute of the third round, but Ennis unloaded a left-hook, right-uppercut combination later in the third that rocked Lipinets.

Ennis backed Lipinets into the ropes several seconds later and unloaded power punches on his vulnerable opponent.

Ennis began the second round in a southpaw stance and quickly drilled Lipinets with a left to the body. He then clipped Lipinets with a right hook as Lipinets pressed forward.

Lipinets landed an overhand right to Ennis’ jaw later in the second round, but Ennis took that shot well.

Ennis established his jab and switched stances during the first round. He landed a left to Lipinets’ body late in the first round and followed up with a right hook up top.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.