David Benavidez put on a show with Canelo Alvarez sitting ringside on Saturday night, moving up 25 pounds in weight and dominating former sparring partner Gilberto 'Zurdo' Ramirez.
He twice sent Ramirez to the canvas, including knocking him out late in the sixth round to win the WBA and WBO cruiserweight titles and become the first boxer to win championships at 168, 175 and 200 pounds.
Benavidez (32-0, 26 knockouts) not only remained undefeated but showed why he was favourite over Ramirez (48-2, 30 KOs) with the first stoppage loss of his career at the T-Mobile Arena in Las Vegas.
Ramirez was taken to a hospital to receive a head scan, according to Jane Murcia, communications director for Golden Boy Promotions.
"He's in good spirits and has a swollen eye," Murcia said. "There's no determination of a fracture at this point."
Benavidez has chased Canelo with hopes of setting up a showdown, but Alvarez never agreed to it and it has been looking unlikely to happen. Benavidez didn't waste the opportunity to make the case yet again.
"I see Canelo in the building. Let me just ask the fans this. Do you guys want to see Canelo versus David Benavidez?" the man known as 'The Mexican Monster' asked, drawing a roar from the crowd.
"Enough said. That means we can't leave that fight on the table. I have respect for Canelo. He's a great champion. I'm a great champion, too. Let's do it."
Benavidez said he would be willing to go back down in weight to make it happen.
"I'm still champion at 175," Benavidez said. "I'm champion at 175 and 200. So if they want to come get it at 175, let's get it at 175."
Benavidez, even when being backed down by Ramirez, delivered his signature rapid-fire combinations, usually pelting his opponent's head.
A right hand to Ramirez's head in the fourth staggered him, and Benavidez went for the knockout but settled for the knockdown at the end of the round when Zurdo went down to his left knee.
Then two rounds later, Ramirez again went to a knee. This time, the fight was over.
"We came up together," Benavidez said. "We came up sparring together. I got him ready for his world championship fights. He got me ready for my world championship fights. I just want to say I love Zurdo Ramirez, but, you know, it is what it is in here. There's only one 'Monster'.
"I knew I wasn't going to be able to overpower him because it was my first time coming up to 200 pounds.
"So I knew I had to use the gifts that God gave me: speed, power, movement, punch selection and IQ. That's exactly what I did."
In the co-main event, WBA super middleweight championship fight, Jaime Munguia (46-2, 35 KOs) upset title holder Armando Resendiz (16-3, 11 KOs) by winning a resounding unanimous decision.
Munguia - the former WBO junior middleweight champ - was the aggressor from the start and won by scores of 117-111, 119-109 and 120-108.
"It feels great to have this championship belt with me, but this is just the beginning," Munguia said. "I'm excited for what comes next. We are ready for big challenges and great fights."