This Sunday's UFC 248 event is headlined by two title fights. One female, one male; one with the potential to be fighter of the year, another with the potential to be a disaster – both significant to their respective fights, their divisions and the UFC at large.

Women's Strawweight: Zhang Weili (C) vs. Joanna Jedrzejcyzk

The women's strawweight division is without question the most exciting division in all of combat sports right now.

It combines the rawness of women's MMA – a phrase intended as a compliment here – with what seems to be the largest and most accepting weight class for female athletes.

The proof of this is that there is no undisputed top dog: Valentina Shevchenko is slicing through flyweight, Amanda Nunes is evolving every fight at bantamweight and at featherweight, a weight division otherwise totally bossed by Cris Cyborg.

But just because there is no current undisputed best at women's strawweight, it doesn't mean there can't be an undisputed best at women's strawweight, and that's the position that current champion Zhang Weili seems to be gunning for.

With a record of 21-1-0, undefeated since 22 fights ago, Zhang has the record to back it up and her title winning performance against Jessica Andrade at UFC Shenzhen last August certainly made an impact.

Andrade, known for her aggressive style, was bullrushed by Zhang, who managed to squeeze a whole highlight reel worth of footage into her 42-second victory.

Punches, kicks, knees, elbows and a clinch; all aspects of her stand up game were on show and delivered with ferocity and precision.

She landed 76 percent of her significant strikes and split them almost entirely in half between distance and range, with the difference being made up for the ground strike finish.

To sum up her opponent, Joanna Jedrzejczyk, having become friends with Conor McGregor, realized she needed to rebrand herself as very few people could correctly pronounce, and even less spell, her Polish surname.

She accepted two nicknames that, together, perfectly encapsulate her fighting career: Joanna Violence and Joanna Champion.

With a perfect 8-0 record, Jedrzejczyk took on Carla Esparza and won the UFC Women's Strawweight Championship with a second-round TKO at UFC 185 on March 14, 2015, and held onto it for five defenses until November 4, 2017 when she lost to Rose Namajunas.

Technically, the TKO loss was unexpected. Until then, Jedrzejczyk had handily defeated all comers, picking them apart over the full five rounds until they were bruised, battered and bloody.

With the benefit of hindsight, it was Jedrzejczyk's mentality that gave her away; when fighters start talking about retiring undefeated, it often backfires (i.e. Ronda Rousey) because if you start talking like you cannot lose, you thinking you can't lose is the perfect way to start slacking on training and missing the small, vital things a hungrier fighter will use to win.

Since then, she may have only won two out of five, but each loss has had a very tangible humbling and educational effect on the former champion.

In her performance in the number one contender's bout against Michelle Waterson at UFC Tampa, she looked every bit as dominant and dangerous as she was when champion.

Styles make fights and this is a throwback to the extreme boxer vs grappler days of the early UFC.

In the red corner is Zhang, who likes to bulldoze and in the blue corner is Jedrzejczyk, an assassin who will take 25 minutes to shatter her opponent's face.

The contrast alone guarantees a thrilling encounter.

Men's Middleweight: Israel Adesanya (C) vs. Yoel Romero

Anderson Silva's legacy had been on precipitous decline since he lost the middleweight belt in embarrassing fashion to Chris Weidman in 2013 and then continued to make a mockery of himself and his legacy in all ensuing fights. However, when Israel Adesanya beat him at UFC 234 on February 10, 2019, everyone could feel it in the air. His era was over.

Once considered the most fearsome fighter in the UFC because of his iron jaw, borderline non-Euclidean striking angles and in ring taunting, at UFC 234 he was on the receiving end of that exact treatment.

Adesanya ran circles around him and it figuratively and literally made him dizzy with all his movements.

In the course of three rounds, Silva was chopped down from being considered a great fighter past his prime to a human punching bag and Adesanya became a star.

From there, Adesanya was (rightfully) catapulted to the top of the division and at UFC 243 in Melbourne, Australia, he knocked out the returning Robert Whittaker in the second round to become UFC Middleweight Champion.

He also went on to call out UFC Light heavyweight Champion Jon Jones, a gutsy move by anybody's standards.

The problem with having such a dominant force rising through the ranks is that, once they become champions, there's nobody left to fight, a situation exacerbated by the UFC's matchmaking policy that is skewed towards making big, headline-grabbing fights over ones earned by professional rankings.

With everyone at the top either injured (Paulo Costa), facing retirement, challenging other divisions for no real reason or ducking contenders (everyone else), it was down to Adesanya to handpick his first title defense, and he chose Yoel Romero.

At 42 years of age and on a two-fight losing streak, it's easy to see why Adesanya would choose Romero, and it's also the reasons why he should perhaps be scared of facing Romero too.

Though his record is 13-4-0, this is only his second title fight following a loss to Robert Whittaker at UFC 213 and almost certainly his last so he will give it his all.

He's a bizarre fighter who is freakishly powerful yet only uses it in bursts, as Lyoto Machida, Chris Weidman and Luke Rockhold will attest to.

In all of those fights, Romero hung back and let his opponents chip away at him before finally picking his spot and annihilating them with a highlight finish.

Machida had his head bounced off the canvas with a series of elbow shots; Weidman was hit by a hard flying knee, which caused him to collapse downwards and knock himself out on his own knee and Rockhold had his jaw broken by a series of uppercuts.

What unites these lethal moves is that they spawned out of nowhere, catching their victims totally off guard.

Adesanya's thought must be that he can take advantage of Romero's vast downtime to pepper him with punches and kicks, and if he can do that, it will be a five round sparring session for the champion that doesn't prove anything we don't already know.

And if he loses, it will likely be in a debilitating fashion to someone not considered a top contender. The risk is there, the reward is not.

(Video editor: Li Chenqi)