ONTARIO, Calif. — While the crowd booed and Josesito Lopez argued in vain with the referee, Andre Berto leaped on the ropes and raised his arms.

A little drama wasn't about to stop the former champion from celebrating a cathartic victory on his road back to the top.

Berto knocked down Lopez twice in the sixth round Friday night, winning their welterweight bout by stoppage when referee Raul Caiz Jr. swiftly ended it.

Berto (30-3, 23 KOs), who once held the WBC 147-pound belt for three years, landed several big shots in the decisive round of his second straight victory following consecutive defeats. The first loss in that sequence was a brutal decision against Robert Guerrero in late 2012 in this same ring at Citizens Business Bank Arena, one hour east of Los Angeles in Lopez's backyard.

"I just knew that he was getting off some shots, and I knew I was in his hometown," Berto said. "I knew they were probably giving him some rounds, but as a fighter, you have to see your opponent. We've got 12 rounds, and I'm going to get you. After round by round, I could tell he was slowing down, and eventually I was going to get him."

That resilient effort against Lopez (33-7) was heartening for a fighter who struggled with injuries while losing three of his previous five bouts and falling from the sport's heights.

Lopez got off to a strong start in front of his local fans, but Berto injured Lopez's right eye while showing off his power and hand speed in the third round.

After staggering Lopez early in the sixth round, Berto connected with a right hand to the temple and sent the taller Lopez sprawling. After beating the count, Lopez went down again during a close exchange in another corner, and Caiz waved off the fight.

"Looked like he was pretty much out," Berto said. "After the first knockdown, I didn't know if he was going to get up, but if he did get up, I was going to drop some heavy stuff on him."

Lopez and trainer Henry Ramirez argued vociferously against the stoppage. Lopez also lost a fight to Marcos Maidana on a debatable stoppage in June 2013, but said he felt "this one was 10 times worse."

"When I fight the best fighters, the best comes out in me," Lopez said. "I don't feel like I got dominated, blown out. I think this would have been a different story if this fight had continued."

Berto earned an interim title belt with the victory.

Former welterweight champion Shawn Porter stopped Ecuador's Erick Bone in the fifth round during the second show put on by Premier Boxing Champions, guru Al Haymon's grand scheme to put the sport back into the television mainstream with eye-catching shows and action-packed matchups on several networks.

Bone (16-2) stepped into the co-main event after Roberto Garcia missed weight Thursday night. He did fairly well as a late replacement against Porter (25-1-1, 16 KOs), who was simply too strong in his first bout since losing his IBF belt by decision to Britain's Kell Brook last August.

Former title contender Chris Arreola also won a narrow unanimous decision over unknown Curtis Harper in a wild bout between two hefty heavyweights.

Arreola (36-4) had a harrowing night in his return from a loss to Bermane Stiverne for the WBC title last May. Harper (12-4), who took the fight one week ago, got knocked down and nearly finished in the first round.

Yet Harper recovered and eventually tagged Arreola with numerous unblocked punches in an entertaining brawl, repeatedly staggering the iron-chinned favorite.

Following up on last week's debut in Las Vegas, PBC again created a lavish presentation to introduce its fighters, who walked alone to the ring down a long, winding ramp in front of an elaborate lights display.

Spike also used the broadcast as a chance to hone its new wrinkles in the time-tested presentation of combat sports on television, including a large aerial rigging that provided a 360-degree view of the fight. Referee Jack Rees and trainer Kenny Porter, Shawn's father, both wore cameras strapped to their heads to provide an unusual perspective on the ring.