SAN ANTONIO -- Jesus Soto Karass stopped Andre Berto with a left hook in the 12th round of their welterweight fight Saturday night, possibly ending Berto's once-promising career.
Soto Karass (28-8-3, 18 KOs) surged in the fight from the fourth round as Berto began to lose effectiveness from his dominant right side. Though Berto (28-3) floored Soto Karass with a left-hand body shot in the 11th, Berto couldn't sustain the rally.
"In the fourth round I tore (something) in my shoulder," Berto said. "I'm a warrior. I don't quit. I'm always going to put it all on the line."
By the end of the 11th, Soto Karass recovered from the knockdown and bloodied Berto's lip, and the Mexican ended it on a technical knockout with the left hand 48 seconds into the final round. The referee stopped the fight immediately when Berto hit the mat -- to Berto's dismay.
Soto Karass led on one card, Berto on another, and the third judge had it even.
"I thought I was winning the fight," Soto Karass said. "But my corner told me to go with everything. I had to go with the knockout to avoid any problems with the judges."
Berto, who won his first 27 professional fights, has lost three of his last four bouts. At one time, enjoying his status as WBC and IBF welterweight champion, he was mentioned as a possible opponent for Floyd Mayweather.
Soto Karass used a strong fourth round, when he switched from long overhand rights and moved in for a series of strong punches. Prior to that, Berto was scoring with short rights to the head that stunned Soto Karass.
But that attacked ended quickly. He appeared to lose effectiveness with his right hand. He counted on his left so much that when he swung a wild overhand from that side in the fifth round, he missed Soto Karass and fell off balance and slipped to the mat. Just a few moments earlier, Berto has cringed as he was leading with his right shoulder while he had Soto Karass on the ropes.
On the undercard, Omar Figueroa Jr. of Weslaco (22-0-1) became the interim WBC lightweight champion in a unanimous decision over Japan's Nihito Arakawa (24-3-1). But it was a bruising fight, with the brawling Figueroa punching Arakawa into two eight counts and a welt over the eye and Figueroa trudging through most of the fight with a nasty gash on the bridge of his nose from what was ruled an accidental head butt.
Keith Thurman (23-0, 19 KOs) took the interim WBA welterweight belt from Argentina's Diego Chavez (22-1) with a 10th-round knockout. Thurman, who started slowly and had a bloody nose through the opening three rounds, rallied and sent Chaves to the mat with a solid body shot in the ninth. Thurman finished it off 28 seconds into the 10th when he caught the slowed Chaves along the ropes with a right to the forehead.