Who will fill Floyd Mayweather's shoes?

LAS VEGAS -- Floyd Mayweather capped off a brilliant 19-year career Saturday by clinically outboxing Andre Berto at the MGM Grand Garden Arena.

Walking away after equaling Rocky Marciano’s hallowed record of 49-0, Mayweather left behind a gaping hole at the top of the sport.

With Mayweather having achieved the rare feat of serving dual roles as boxing’s pound-for-pound king and its biggest draw, there remains no easy choice to replace him. Yet the end of one era always provides opportunities for others to make a run at the top.

So who has the best chance to become the face of the sport over the next few years? Let’s take a look at the top five candidates:

. Gennady Golovkin, middleweight titlist, (33-0)

His inability to land the biggest names as one of boxing’s most avoided fighters hasn’t slowed Golovkin’s climb up the P4P ladder. With an appealing combination of power, humility and charm, the Kazakh slugger has slowly become the darling of boxing fans since making his U.S. debut in 2012. He has also unleashed a reign of terror on the middleweight division with 14 consecutive title defenses and a whopping 20 straight knockouts overall. At age 33, Golovkin needs to move quickly to capitalize on his small window of opportunity. But just one month away from headlining his first pay-per-view in a unification fight against David Lemieux, GGG is on his way.

Canelo Alvarez, junior middleweight, (45-1-1)

Despite residing on the outside of most P4P lists, the red-haired Mexican sensation more than holds his own in marketability as a proven pay-per-view brand. At 25, he’s already the face of boxing’s most passionate fan base, and he only stands to improve his critical reputation should he defeat middleweight champion Miguel Cotto in their long-awaited Nov. 21 showdown. A victory over Cotto could also set him up on a collision course with Golovkin, where legit superstardom would await the winner.

Felix Verdejo, lightweight, (18-0)

We are still a year or two from finding out exactly what we have in the 22-year-old firecracker with the good looks and exciting style. But considering that fans of his native Puerto Rico have been waiting to anoint Verdejo for years as the successor to the lineage of names like Wilfred Benitez, Felix "Tito" Trinidad and Cotto, we have a pretty good feeling he’s the real deal. The unbeaten lightweight and 2014 ESPN.com prospect of the year has the most promise of any young fighter to achieve equal critical and commercial success.

Errol Spence Jr., welterweight, (18-0)

Publicly endorsed by none other than Mayweather himself in recent months as the eventual successor to his P4P throne, the jewel of the 2012 U.S. Olympic class has very much looked the part throughout each step up in class. The soft-spoken Spence, 25, clearly lacks Mayweather’s gift for gab as a marketer. Yet his refreshing balance of unwavering confidence and humility has him much more likely to play the role as All-American babyface instead of a Mayweather-esque heel. Inside the ring, the southpaw has also found the perfect balance between boxing and punching, with championship-level poise at a young age.

Anthony Joshua, heavyweight, (14-0)

The 2012 Olympic gold medalist from England has potential crossover advantages that come with being the heavyweight division’s “next big thing.” With 14 knockouts in as many fights, Joshua has the power to match the intimidating look of his 6-foot-6 muscular frame. But he’ll likely need the help of a heavyweight renaissance in order to produce enough marketable opponents to see him maximize the potential of his brand, particularly in the U.S. Regardless, Joshua is the most complete prospect the division has seen in a long, long time.