By Jake Donovan

Keith Thurman was determined for two things to come out of his welterweight showdown with Luis Collazo: return to his old knockout ways, and present a formidable future challenge to pound-for-pound king Floyd Mayweather Jr.

The unbeaten titlist did in fact pick up his first knockout win in more than a year, and went out of his way to openly challenge Mayweather, who is still in the market for an opponent for a planned September 12 fight in Las Vegas. Whether or not either instance rallied public support is another matter altogether.

Headlining the first edition of Premier Boxing Champions (PBC) on ESPN, Thurman forced Collazo to quit on his stool prior to the start of round eight Saturday evening at USF Sun Dome in Tampa.  The bout served as Thurman's first fight near home (originally from Clearwater, trains out of the Tampa/St. Petersburg area) in nearly six years, and it showed with a packed house on hand for the latest entry of a "#FreeBoxingForAll" campaign being led by PBC and series creator, adviser Al Haymon.

“This is great for me to pull this off at home," Thurman said of the homecoming and the expectations that came with fighting in front of his adoring public. "There was lots of pressure and hype. I gave it my best and I came out with the win."

The early rounds suggested perhaps more of the same recent version of Thurman, who has been forced to go the distance in each of his past two starts. The unbeaten knockout artist was taken the full 12 rounds by Leonardo Bundu last December, and then by former welterweight titlist Robert Guerrero in March.

The latter bout served as the very first PBC headliner, which aired live in prime time on NBC. Thurman's shoulder was again tapped to help launch the series on a new network. The main event players had somewhat of a tough act to follow, as a major upset in the co-feature produced a surprise ending as Willie Nelson rallied to knockout previously unbeaten Tony Harrison, an outcome that helped overshadow an otherwise dull affair.

Thurman and Collazo both did their part to keep the bout entertaining throughout, even if not always doing so together. Collazo offered little offense in the first few rounds, fighting behind a peek-a-boo defense as Thurman was sharp shooting early in the bout.

What was lacking was the threat of a knockout, although Thurman's punching power could change that perception in an instant. However, it was Collazo who raised the stakes and nearly produced a knockdown, coming out of nowhere to hurt Thurman late in round five.

A body shot visibly hurt Thurman, invigorating a previously reluctant Collazo to go in for the kill. The 34-year old southpaw, on the wrong side of his prime and nearly a decade removed from his time spent as a former titlist, moved in with the intention of ending the fight, repeatedly hurting Thurman to the point of forcing the unbeaten local favorite to clinch his way out of trouble in order to survive perhaps the worst round of a career filled with promise.

"He caught me with a left hook uppercut hybrid shot in the fifth and knocked out almost all of my wind," Thurman admitted afterward. "It was an excellent shot by Luis. I endured like a champion though."

The sequence breathed new life into what had been a one-sided affair to that point. Alas, it was Collazo's last hurrah, and perhaps the final great moment of his lengthy career.

"I was trying to set up body shots any way I could," Collazo said of the sequence that nearly produced—had he managed to stop Thurman—by far the biggest upset of the year. "I saw him moving to the left and was trying to catch him just right. I wish I had more time in that round.

Thurman resumed control in round six and never looked back. By round seven, Collazo was forced to contend not just with Thurman's accurate power shots, but also a gushing cut over his right eye as well as compromised vision.

The latter part was key in the fight eventually being stopped. A visit from the ringside doctor prompted a question-and-answer session that ultimately led to the bout's anti-climactic conclusion.

"Are you alright to continue," Collazo was asked by the ringside physician prior to the start of round eight.

The answer provided said all you needed to know about where he stood on the matter and in his career.

"That's up to y'all," Collazo responded, the type of answer that is almost always interpreted as a fighter being done for the night. "I can't see."

It was enough for the doctor to inform referee Telis Assemenios that the Nuyorican was done for the night—and perhaps forever in the way of relevant welterweight action.

While it was undetermined whether Collazo's cut came from a punch or headbutt, the fact that he waved the surrender flag was enough for the ring officials to declare the bout a technical knockout. The official time was 0:01 of round eight.

Thurman advances to 26-0 (22KOs), picking up his first stoppage win since forcing faded Julio Diaz to quit after three rounds in their clash last April.

Collazo falls to 36-7 (19KOs), endurng just the second stoppage loss of his career. His previous defeat inside the distance came way back in 2002, just shy of his 21st birthday. Some 13 years later, this loss carried far more weight in determining his future in the sport, although his reasoning for choosing not to continue the fight was so that he could, in fact, continue as a prizefighter.

“If I would have come out of my corner again I probably would have gotten caught with some unnecessary shots, and I didn’t need that," Collazo admitted afterward. “Thanks to my fans for all the love and support. Sorry for letting you all down tonight, but I want to fight again so we decided not to continue.”

There's no question that Thurman will continue on, and at the top level as he remains a star on the rise. Saturday's performance may not have done much to enhance his potential, but that didn't stop the unbeaten 26-year old from calling out every major player in and around his weight class.

“We want anybody that we can get at the top of the welterweight division; Mayweather, Pacquiao, Porter, Khan, Bradley, Maidana," Thurman insisted.

Of course, there's one fighter in particular that's at the top of the list for any welterweight.

"

"I'm a young, strong champion, Floyd. Come get it," Thurman challenged Mayweather after the fight. "I'm undefeated like you, baby. Come take my '0' baby. I'm ready."

It's doubtful that Mayweather's next fight—slated for September 12 against an opponent to be determined—will come against Thurman, although the good news is that few if any believe that it will in fact serve as the last ever fight of his incredible career.

That's good news for Thurman, and perhaps for those who may feel that he is in fact not ready for such a fight—yet.

Jake Donovan is the Managing Editor of BoxingScene.com. Twitter: @JakeNDaBox