LAS VEGAS -- You can forgive Canelo Alvarez's most cynical critics for believing that until Saturday night, he was just another pretty face.

The Mexican star was barely an adult when his good looks and marketable red locks earned him recognition as the face of boxing's most passionate fan base. But despite doing plenty to tease worthiness of the recognition hoisted his way in recent years, Alvarez's case for critical respect had holes.

To his harshest detractors, he was far more popular than elite; in his biggest wins to date, more lucky on the scorecards than good.

But the road to legitimacy has long been a bumpy one, with the kind of twists and turns that threaten to derail the most promising of careers from achieving their full potential. Coming up embarrassingly short two years ago against Floyd Mayweather, Alvarez knew that feeling well.

Lost in the buildup to Saturday's middleweight championship bout against Miguel Cotto was how much a loss would have threatened the credibility of everything Alvarez had previously built. But the bigger, stronger and younger fighter made sure we never found out.

Alvarez relied on every one of his advantages to outpoint Cotto (40-5, 33 KOs) by unanimous decision at the Mandalay Bay Events Center. By doing so, Alvarez (46-1-1, 32 KOs) accomplished something far more important than winning a lineal title in a new weight class -- he removed any lingering doubt.

The process of passing the torch in boxing has typically been done by a younger fighter unseating an aging veteran to acquire a portion of his stardom. It's a cosmic transaction of sorts. But popularity was something Alvarez has never lacked.

By convincingly beating the more experienced Cotto, 35, and landing the harder shots throughout, Alvarez validated himself as an elite fighter. He also answered questions about his stamina, poise and ability to carry out a game plan on the biggest stage.

The victory showcased just how much Alvarez, at 25, has improved with each fight.

He still may not cut off the ring or throw enough punches to satisfy those who have long wished he would walk down his opponents in a manner more fitting of a traditional Mexican warrior. But Alvarez is clearly coming into his own by utilizing his own style, which mixes craft with power.

If Alvarez hadn't yet reached this level of maturity, the rejuvenated and game version of Cotto under trainer Freddie Roach on Saturday would have been savvy enough to expose that. Yet Alvarez's power shots were crisp as he mixed in uppercuts and short right hands in close. He was plodding, yet steady in his attack, with each clean shot slowly zapping Cotto of his firepower in return.

He also stripped Cotto of his most dangerous weapon -- his patented left hook -- from the very beginning with responsible defense by stuffing body blows with his right hand and swiveling his upper body away from head shots.

The victory stamps Alvarez's case for serious consideration among the sport's pound-for-pound best in the kind of victory that will give him a strong case for fighter of the year honors. But as the saying goes, there are levels to this, and with Canelo moving up to the elite status, a new set of questions emerges.

The former unified junior middleweight titlist defeated an aging Cotto, who hadn't weighed in within five pounds of the middleweight limit in each of his three fights in the division. So how will Alvarez, who has fought his last four bouts at catchweights of 155 pounds, fare at the bigger weight?

Alvarez likely won't get much chance to test the waters where he stands now, firmly in the crosshairs of unbeaten unified titlist Gennady Golovkin, who is the mandatory challenger for Alvarez's WBC title and has lusted for a shot at unifying all four titles and capturing the lineal crown.

But to his credit, Alvarez remained consistent with the dare-to-be-great philosophy he acquired from promoter and mentor Oscar De La Hoya by responding to questions about facing Golovkin after Saturday's fight with an open willingness.

Will Alvarez likely lean on the benefits of being an A-side fighter, even to the point of forcing Golovkin to come down a few pounds at a catchweight? It's very likely (as De La Hoya, himself, has done before). But Alvarez has done nothing as of yet for us to doubt his sincerity about taking on the challenge.

This is the reputation Alvarez has worked hard to build by consistently taking on the most difficult tests available while not being afraid of defeat. In many ways, he's this generation's De La Hoya, who gave boxing fans one big event after another over a Hall of Fame career.

And in the aftermath of the Mayweather-Manny Pacquiao era, with boxing in need of crossover superstars willing to square off against each another for the betterment of the sport, Alvarez's victory over the equally respected Cotto was a plus for the sport.