By Jake Donovan

The resurrection of Jesus Soto-Karass' once-fleeting career could have very well produced the end of Andre Berto's days as a relevant welterweight player.

Soto Karass put himself closer into title contention than at any other point in his lengthy career after scoring an upset 12th round stoppage of Berto in their Showtime-televised main event Saturday evening at the AT&T Center in San Antonio.

The threat of a shocker came right from the opening bell, as Berto - now training with Virgil Hunter - had no clue how to slow down the bum rush presented by his determined foe. Power punches scored repeatedly for Soto Karass, who found Berto's leaky defense and poor execution of the shoulder roll technique all too inviting.

Berto is nothing if not a warrior, however. The former welterweight titlist saw his eyes puff up early in the fight, but sandwiched in between rough moments in rounds one and three was a fun power punching display in the second. It was enough to let Soto Karass know he'd have to step up his game if he were to live up to his pre-fight promise of fighting hard yet smarter.

He would do just that.

Berto managed to avoid a knockdown in round five, but the slip and fall to the canvas wound up badly damaging his left shoulder. The Floridian was forced to spend the rest of the night fighting with one arm, but at no point was willing to quit. His corner reminded him of who was in front of him - a hint that Soto-Karass, while brave for days, has a history of falling short at the top level.

The motivational speeches in between rounds wasn't enough to offset the early damage done, but worked in the latter stages of the bout - at least until the fight-ending sequence. The four rounds preceding the shocking ending saw Berto somehow turn a disastrous rout into a competitive fight.

A late rounds rally was punctuated by an 11th round body shot knockdown which Soto Karass claimed was the result of a low blow. Replays supported the call made by referee Jon Schorle, though its impact left a bitter taste in the mouths of many when the final scorecards were revealed.

The 10-8 sequence left Berto ahead on one card (105-103), even at 104-104 and down 105-103 on the third heading into the 12th and final round. In other words, the fight was still very much on the table despite the disastrous start and the mid-rounds energy.

Soto-Karass finished the fight as if he literally knew the score. A perfectly placed left hook put Berto on the canvas early in the 12th. The ex-champ was up well before the mandatory count reached eight, but wobbled upon rising and his vision severely compromised from 11 rounds worth of impact. His body language prompted the third man to stop the contest.

The win advances Soto Karass to 27-9-3 (18KO), having now scored two straight victories following last year's brave showing in a knockout loss to Marcos Maidana.

Berto suffers the first knockout loss of his career, and his third overall defeat in his past four fights in dropping to 28-3 (22KO). The bout was his first since last November's points loss to Robert Guerrero, but quite possibly his last as a headlining act.

Jake Donovan is the Managing Editor of Boxingscene.com, as well as a member of Transnational Boxing Ratings Board and the Boxing Writers Association of America. Twitter: @JakeNDaBox