LAS VEGAS – A loud “thwack” stops any murmuring that could be heard inside the Pound 4 Pound Boxing Gym in Las Vegas.

Junior middleweight champion Sebastian Fundora shovels a hook into a pad, held by his father and coach Freddy, and then he cracks a hook in behind. The shots sound like the base of a thick tree splitting, and Fundora works up a sweat for the media during a short session ahead of Saturday’s fight at the Mandalay Bay against Chordale Booker, who is challenging him for his WBC and WBO titles.

The torque on Fundora’s punches has even veteran observers shaking their heads, not wanting the leather to land anywhere near them, and as he puts on his thick-rimmed black spectacles, and makes his way over to the waiting media, he is asked about both his technique and generating power from the spindly legs that carry his 6ft 5 1/2ins frame.

“That’s absolutely true,” smiles Fundora, talking about torque, performance and still improving. “The older I get, the more I feel like I’m learning in the sport. I’m 27 years old. We started this sport very young, we started professional very young, so I’m still growing into this man body. I feel like I’m fully a man now and with these titles, whether I like it or not, I’m going to have to learn how to box now.”

Fundora has shown different sides to his game, but there is an inherent passion to fight – and fight hard.  

Not shy of confidence in the first place, his conviction in what he does has only been enhanced at having championships around his waist.

Now 21-1-1 (13 KOs), the 27-year-old explained: “I feel like, with this new confidence, not that I didn't have confidence before, but with this extra confidence that I have now being a champion, it just puts me that much higher in my head, in my heart, to be in the ring and at a level like this... It could be pride. It could be the fact that we [Sebastian and his sister, Gabriela] actually achieved our dreams of becoming world champions.”

He believes he is a better fighter now than he was when he won the titles here in Vegas a year ago, but admits to being frustrated at not being able to get back out in 2024. Rumoured fights and fight dates, most notably with Errol Spence – who appeared in the ring after the Tszyu contest – amounted to nothing.

“But the business of boxing didn’t let that happen,” Fundora says. “So this year, now we’re in March again a year later, hopefully we can get more than one fight this year.”

But he has stayed in shape and for this camp has trained up in the snow-capped mountains, channelling his inner Rocky. 

“I live in the mountains,” said the Californian. “The mountains don't slow down for anybody, so I had to do work. We’re doing everything. We’re chasing bears,” he grins.

“We’re shooting deer. It's hard. It’s not for the faint of heart. This is definitely a Rocky-style training camp.” 

Booker, meanwhile, has embraced his role as the underdog, saying the pressure is off him and expectation could weigh heavy on the champion. And at the same time, Fundora is a decorated member of one of boxing’s richest cast lists. The depth of talent at 154 is almost unmatched in the sport.

“Underdog? Of course,” he says of Booker’s claims. “I think the person that fights the champion is always going to be the underdog. The last fight [against Tszyu] we were the underdog but, you know, look how that came out. We don’t look past Booker. This fight is what we’re focused on. We’ve been focused on this for three months now. Come Saturday night we’re going to show you what we need to do.”

Asked about his thirst for tough fights, Fundora said “enjoying” was the wrong word to describe how he feels about inflicting punishment. He is softly-spoken, has a quick smile and does not get lost in hyperbole. He throws a lot of punches in each fight, that’s his modus operandi, and there is no desire to slow at this stage.

“I just do what I do,” he adds. “If I’m not the one throwing, he’s going to be doing that to me. That’s the name of the game: hit, don’t get hit. The best defense is offense. If you’re not punching, they’re going to be punching you. There’s only one thing in boxing. Punch and that’s all there is to it. Simple. You got to throw punches.”

Such straightforward analysis has stood him in good stead, to the point that he is the marked man in the division. He has the most championship hardware. 

The media workouts end, as they sometimes do, with the fighters sharing a head-to-head, and Fundora’s with Booker ends as most Fundora head-to-heads do, with the fighters and those watching chuckling at the height disparity.

But, make no mistake, a slip up for Fundora on Saturday would be costly.

His is the name many mention when they talk about fights they covet, and he welcomes such pressure.

“I think that’s perfect,” he says. “Without these titles, it’s a little harder to get fights. No one really wanted to fight us. Now that we have these titles, you’re going to have to fight us if you want to become champion.”