SAN ANTONIO -- Marcos Maidana overpowered the heavily favored Adrien Broner to take the WBA welterweight championship, knocking him down twice in a unanimous decision Saturday night at the Alamodome.

The target of heavy trash talk leading up to the fight, Maidana was dominant in handing the brash Broner his first loss in 28 bouts. After the judges' scores of 115-110, 116-109 and 117-109 were announced in favor of the Argentine star, Broner ran out of the ring.

"I had to show a lot of heart to win this fight," Maidana said. "I did what I had to do to win."

Broner is nicknamed "The Problem," but Maidana (35-3) had the answer with power that the three-time world champion had never faced before.

"I'm OK. I'm still the three-time world champion in three different weight classes," Broner said. "Tonight, Maidana was just the better man, but we fought a hell of a fight. I hope the fans got what they deserved. ... I'm still going to live like we won the fight. I'm still going to party."

With the victory, Maidana set up a possible fight against Keith Thurman. On the undercard, Thurman stopped Jesus Soto Karass in the ninth round.

Maidana left little question of what he wanted to do, landing 231 of 663 power punches while connecting on only 38 jabs.

The power stunned the confident Broner, who was unable to use the fluid counter punching that had resulted in 22 knockouts and made him one of the sport's top stars.

"I'll tell you one thing, make a rematch," Broner said. "I don't need a warm-up fight. I want a rematch."

Maidana staggered Broner early in the opening round with an overhand right to the back of the head, causing the Cincinnati fighter to stumble trying to regain his footing. Broner attempted to wrap up Maidana as he attempted to wrestle free to land more power punches.

Not even elbows, pushing, head-butts and more dirty tactics from both Marcos Maidana and Adrien Broner could mar this fight. Ronald Martinez/Getty Images

Maidana spent the entire opening round charging at Broner, trapping him against the ropes and throwing powerful combinations.

Maidana sent Broner tumbling into the ropes early in the second round with a lunging left hook to the chin. After a standing eight count, Broner charged and wrapped up Maidana's upper legs in an attempt to recover.

Maidana landed 57 punches in the opening two rounds to only 13 for Broner, according to Showtime. Broner regained his balance after the second round, spending the next five rounds trading punches and clenches before Maidana regained control.

"Broner is a very good puncher," Maidana said. "He's a very good boxer, very good puncher. Yes, I felt his blows."

Maidana floored Broner in the eighth round with a left to the midsection and an overhand right. After a standing eight count, Broner again went to the canvas after taking a head-butt to the jaw. Amid heavy booing, Broner remained on the canvas and in a corner for about three minutes before returning to action.

In the ninth round, Maidana again stunned Broner, unleashing combination after combination that Broner was struggling to avoid. Broner regained his feet in the 10th round but was only able to exchange blows with Maidana the remainder of the fight.

"I don't think he was on today," said Broner's trainer, Mike Stafford. "I thought it was a little closer than (the judges) had it, but I just don't think he was on tonight."

On the undercard, Thurman (22-0) stunned Soto Karass (28-9-3) with a left hook to the chin that had the Mexican fighter out on his feet. Defenseless, Soto Karass took four more heavy blows before the referee stopped the bout.

Soto Karass caught Thurman with an overhand right to the chin in the opening minute of the bout, staggering the Clearwater, Fla., fighter. Soto Karass followed it with another crushing right, but Thurman withstood the flurry and delivered his own staggering shots to the body and head to close the round.

"He made me bring it out from Round 1," Thurman said. "He was ready Round 1. I was dilly dallying in Round 1, and he turned the lights on and woke me up."

Earlier, Leo Santa Cruz (26-0-1) successfully defended his WBC super bantamweight championship, unanimously outpointing Cesar Seda. The judges scored the bout 116-111, 115-112, 117-110 for Santa Cruz, who landed 43 percent of his power punches in handing Seda his second loss in 27 fights.

Also, Beibut Shumenov stopped Tomas Kovacs in the third round to retain his WBA super light-heavyweight championship. Shumenov, from Kazakhstan, improved to 14-1. Kovacs, from Slovakia, dropped to 23-1.