SAN ANTONIO—If there was any upside to having to train through the holidays, it’s that Jaime Munguia had an additional six pounds to work with for his next fight.

The former junior middleweight titlist comfortably fit into a 160-pound frame (159.4, officially) for his first fight at middleweight, am 11th round stoppage of veteran fringe contender Gary ‘Spike’ O’Sullivan. The win—which aired live on DAZN from The Alamodome in San Antonio, Texas—was preceded by pockets of entertaining two-way action, but with Ireland’s O’Sullivan simply wearing down while the unbeaten former champ looked like he could go another 12 rounds.

“I really felt the difference at 160 pounds,” Munguia (35-0, 28KOs) admitted after the fight. “I felt so much stronger than I have at 154 pounds.”

Munguia managed to boil his 6’0” frame down into a 154-pound uniform long enough to scratch out five successful title defenses, with six total title fights coming in a 16-month clip. Ring activity was promised no matter where he fought, leaving the 23-year old Tijuana, Mexico native to vacate the belt in favor of a lofty ranking at middleweight before stepping foot in the ring.

Fortunately, he justified the positioning in Saturday’s performance, having his way with O’Sullivan (30-4, 21KOs) particularly in the later rounds to enter the mix as a middleweight player.

Naturally, he’s already gunning for the biggest names in the division.

“I want all the best (middleweights),” noted Munguia, who conspicuously left out Demetrius Andrade despite serving as his mandatory challenger. “I want [World middleweight champion Saul] Canelo Alvarez, [two-tour middleweight titlist] Gennadiy Golovkin, [unbeaten middleweight titlist Jermall] Charlo. I want them all.”

Interestingly, all seem to have tentative plans for their own next ring adventures, which could lead to a stay busy fight for Munguia if not a direct shot at the winner of Andrade’s voluntary title defense versus Ireland’s Luke Keeler.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox