The aim of any sportsperson is to be number one.

The best in class. Rated highest among your peers. The champion.

That's where Tim Tszyu now sits.

When the 28-year-old meets American Brian Mendoza on the Gold Coast on Sunday, October 15, he will enter the ring as the WBO world champion.

His first task will be to walk out of that same ring with the same title — far from a done deal against an American who has made a recent habit of upsetting the odds in big fights.

Mendoza, the WBC's interim world champion, is currently in the position occupied until relatively recently by Tszyu, one rung behind the full champion, Jermell Charlo.

The 29-year-old took that ranking by knocking out the previously undefeated Sebastian Fundora in California in April.

Underestimate Mendoza at your peril.

"That was incredible," the affable American said of knocking out Fundora, at Friday's press conference on the Gold Coast, which he was slightly late for owing to a transport mix-up.

"It's a feeling I can't describe. Especially being the underdog and pulling something like that off.

Mendoza said that he had been dreaming about this fight plenty in the build-up, too.

"The common denominator is that I have my hand raised at the end of the night." 

Mendoza said his journey to being a fully-fledged world champion would be his very own Rocky story having fought his "way back from obscurity", and it is that he will bring to the fight.

Contrary to the standard fare of pre-fight madness and amidst the intense heat of the open-air presser at a major shopping centre on the glitter strip, there has been no animosity between the pair in the build-up to this fight.

It's business as usual.

Tszyu might have said on Thursday that he was developing "hatred" towards Mendoza, a barb the American just shrugged off as being part of the game, but even when he was pushed on it, Tszyu was complimentary of his opponent as a man.

He was only hating him because he was standing in his way of retaining his new world title — a shift in mindset common to fighters and Tszyu, in particular, heading into the bout.

Sitting in a crisp white suit in 30-degree temperatures, Tszyu looked every inch the world champion — the new belt sitting in front of him on the bench just adding to the occasion.

Yet the Australian has already stated that he feels like he needs to earn that belt in the ring.

"This is because of one man's bitchiness," Tszyu said of the belt in front of him. "But I want all four."

"I'm in the present moment right now, I'm focused on what really matters — Brian Mendoza. 

Indeed.

Tszyu has, quite rightly, offered scant response to Charlo's verbal jabs from across the seas that he is a "paper champion" who has done "nothing" to earn that belt.

Aside from the fact that those long-range jabs are the only ones Charlo appears willing to throw against Tszyu, having made every excuse under the sun to avoid his obligation to meet the Australian in the ring, Tszyu has done everything asked of him to get into the position he now occupies.

'This is a 50:50 fight' against a 'Tim Tszyu-like' fighter

But there is still that nagging feeling that Tszyu needs to earn his belt in the ring. The proper way.

And make no mistake, he will have to earn it on Sunday.

"I watched him [Mendoza] last night [at the public work-out] and, he's got it," promoter George Rose told ABC Sport.

"He honestly is very Tim Tszyu-like, the way he moves.

"It's a massive risk. We've talked about the fact that he's got knockout power, but there's a lot more to him than just that.

"The one thing with Tim is that he always shows us he's a step up with every fight.

"Depending on who the competition is, depending on who the opponent is, he's always going to step up."

Mendoza clearly possesses significant punching power but the unmitigated violence that Tszyu can unleash on his opponents has been on another level. 

Tszyu has won seven of his last nine fights by way of knockout, often tenderising the body with a level of power that his opponents simply can't handle.

Sure, against Ocampo, it was Tszyu's exploratory left-right combination to the head that initially rocked the Mexican early, before a straight right down the pipe felled him for the first time.

That head-hunting was also on display with explosive effect against Tony Harrison but was interspersed with the type of body punching that tenderised both Terrell Gausha and Takeshi Inoue during their unanimous points defeats.

Mendoza's power should make Tszyu wary of overcommitting early on, lest he risk being knocked down as he was against Gausha, but holding back is simply not his style.

Style, though, could play a significant role in the contest.

Tszyu camp questions the referee

The referee for Sunday's fight, after a couple of changes, will be Phil Austin, the man who was in the middle of the ring when Jeff Horn stunned Manny Pacquiao at Lang Park in 2017.

Austin let plenty go in that fight, which the Tszyu camp was worried could help Mendoza's hands.

"There was concerns raised from the Tszyu camp … given his history with the Horn fight," Rose confirmed.

"He allows a bit of that roughhousing sorta tactics.

"We've got no say over the referee but it's something to think about, because that's going to play into Mendoza's hands.

"We're hoping for a good clean fight and if it is a good clean fight, I think it confidently goes Tim Tszyu's way."

Rose said that although Tszyu's camp was concerned, anything other than the job at hand was not playing on the fighter's mind.

"Tim's focused on Mendoza. Even when we mention future fights or something like that, it all just floats over him.

"His mindset, for him, is that he could fight for nothing in a shed somewhere and he'll fight to win."

Now Tszyu is world champion, the hard work truly begins.