Jessica McCaskill served notice that there is plenty of room for debate in the pound-for-pound race.

The ageless two-division champ successfully defended her undisputed welterweight championship with a fourth-round stoppage of Monterrey’s Alma Ibarra. No knockdowns were scored but traffic was one way in favor of McCaskill, to the point of Ibarra quitting on her stool and not coming out for the start of the fourth round Saturday evening at Tech Port Arena in San Antonio, Texas.

McCaskill vowed to knock out her latest challenger, committing to that plan from the opening bell. The defending welterweight champion and pound-for-pound entrant negated a significant height and reach advantage in favor of Ibarra by working her way inside with her jab, following by overhand rights. Most of her power shots missed the mark but the aggression was enough to keep Ibarra on the defensive. A straight right rocked Ibarra midway through the round, though the Mexican challenger managed to remain upright.

A more potent attack was offered by McCaskill in round two. The Chicago-based boxer showed tremendous infighting skills, cracking Ibarra with a right and immediately dodging a counter shot from her foe. McCaskill continued to find success with her right hand upstairs, to which Ibarra was unable to offer a response.

Ibarra attempted to put her natural size advantage—three inches taller and having spent her career at welterweight and junior middleweight—to good use, though to no avail. McCaskill worked her way out a clinch, showing her physical superiority in moving Ibarra back as the two eventually tumbled to the canvas. McCaskill quickly gathered herself, cracking Ibarra with a left hook and once again avoiding a right hand counter.

The fight ended with a whimper, as Ibarra refused to leave her stool at the start of round four. The single mother who survived an abduction last summer—though costing her a trip to Tokyo as part of Mexico’s Olympic boxing team last summer—told head trainer Javier Capetillo that she was fed up with the course of the fight, insisting that McCaskill was holding rather than fighting and that she just wanted to go back home to her son.

Ibarra falls to 10-2 (5KOs) with the defeat, ending a three-fight win streak.

McCaskill improves to 12-2 (5KOs), picking up her second consecutive stoppage and third overall title defense as a welterweight champ. The 37-year-old—who looks and fights as if she’s at least ten years younger—claimed all of the hardware at welterweight with an upset decision win over then-unbeaten long-reigning champ and pound-for-pound queen Cecilia Braekhus in August 2020, repeating the feat in their March 2021 rematch in Dallas.

McCaskill previously served as a unified junior welterweight titlist, with designs on returning to the weight division more befitting her 5’6” frame. McCaskill has specifically targeted unbeaten WBC/IBF champ Chantelle Cameron (16-0, 8KOs), who has remained active while waiting on the availability of WBA/WBO titlist Kali Reis for their targeted undisputed championship clash.

The bout was the first of a three-title fight DAZN telecast. Headlining the show, locally based unbeaten WBC junior bantamweight titlist Jesse ‘Bam’ Rodriguez (15-0, 10KOs) attempts his first defense against Srisaket Sor Rungvisai (50-5-1, 43KOs), a former two-time WBC champ from Si Sa Ket, Thailand.

Jake Donovan is a senior writer for Twitter: @JakeNDaBox