By Jake Donovan

Well before he announced the September 12 welterweight championship fight with Andre Berto late in the summer, Floyd Mayweather has insisted this will be the final fight of his career. 

If so, he goes out on a high note in terms of the end result. Mayweather coasted—literally, at times—to a 12-round decision over Andre Berto in their Showtime Pay-Per-View main event Saturday evening at MGM Grand in Las Vegas.

Scores were 120-108, 118-110 and 117-111 in favor of Mayweather, whose final performance came in front of an announced crowd of 13,395. It was a far cry from the jam-packed house on hand for his previous appearance, when he and Manny Pacquaio destroyed every financial record in boxing history with their superfight in this very same venue. 

In terms of action, his 12-round performance versus Berto was similar to the night's work Mayweather turned in versus Pacquiao and just about every other opponent throughout his career—more clinical than entertaining. 

Mayweather was a massive betting favorite when the fight was first announced, but enough believers (or bettors who simply love to take a risk on a longshot) placed enough action to bring the odds from 33-1 at the start of fight week all the way down to 18-1 by the time the opening bell sounded. 

There were a lot of disappointed gamblers on this particular evening. The only one in the building who really needed to gamble was Berto, but the former welterweight champion never took the risks necessary to threaten Mayweather's quest to end his illustrious career with his perfect record firmly intact. 

"Experience played a big part," Berto admitted of his inability to crack the code on the sport's best fighter today and of his era. "I was in shape. He was difficult to hold on to. Really slippery. I was coming, but he was real crafty. He did little things to throw me off my rhythm." 

Mayweather has mastered the art of hit and not get hit, but played that out to the extreme on this particular evening. Showtime's punch stats had the pound-for-pound king outlanding Berto 232-83, at times scoring at will with power punches on the occassions he chose to let his hands go. 

At other times, Mayweather was content to move around the ring, dance, converse with the crowd and even taunt his opponent. Perhaps attributable to his holding back was the fact that he injured his left hand—hardly surprising considering he's had brittle hands for most of his career. 

What was a bit surprising—if not for reality setting in—was his reaction when questioned about the injury by Showtime's Jim Grey after the fight. 

"It wouldn't matter if I hurt my left and my right hand; my career is over," Mayweather (49-0, 26KOs) bluntly stated. 

From an action perspective, his career ends on an anti-climactic note. As far as going out on top, that box is firmly checked off as Mayweather showed no signs of slowing down, his combinations and skill set as sharp as ever at age 38 and now 19 years deep in the pro ranks. 

By comparison, Berto looked to be an old 32 next to the reigning welterweight champ. Promises of shocking the world were never fully embraced by the boxing public, with that reality coming to the forefront as early as the opening bell.

More troubling for the former welterweight champ and member of the 2004 Haiti Olympic team was the fact that he and his team never seemed to have a real game plan. Sure, he jabbed, he occasionally applied pressure and smothered Mayweather on the inside. But none if it added up to the tools necessary to take down the best of your generation. 

Worse, adjustments were never made nor was Berto ever given any sound advice from noted trainer Virgil Hunter, best known for his work with another Andre—reigning super middleweight champion Andre Ward, who hasn't lost since he was 13 years old.

This Andre had lost three of his last six and could have used all of the help he could get. It wasn never going to come from referee Kenny Bayless, who allowed excessive amounts of clinching before finally issuing warnings late in the fight. 

It hardly mattered by that point, although some of the most entertaining moments of the fight came when the two were jawing at one another in the later rounds. 

"It was just trash talking," Mayweather noted, though refusing to expand on what was said between the two, instead shifting the conversation to obligatory praise for his opponent. "Andre Berto has heart, a tremendous chin. He wouldn't lay down." 

To that, Berto deserves credit for surpassing expectations that he would get steamrolled. The threat of a knockout never really surfaced until late in the 12th and final round. Mayweather was fighting off the ropes when an uppercut snapped back Berto's head and caused him to do a drunken dance. 

The crowd—most of whom had been booing the prior two minutes of the round—collectively rose to its feet in anticipation of Mayweather scoring his first knockout in four years and going out with a bang.

Instead, he literally ran out the clock, dancing around the permiter of the ring over the final 10 seconds of the fight and of his career. Berto was content to allow it, perhaps pleased with having lasted the full 12 rounds after realizing at some point that he didn't have a prayer of winning. 

"Tonight, I put on a great performance. We pushed him to the limit, but we fell short," said Berto, who falls to 30-4 (23-0). "Floyd is one of the best out there for sure."

At the very least, Mayweather matches one of the best marks in boxing history, joining a small list of fighters who retired both undefeated and as champion. The latest win runs his record to 49-0 (26KOs), matching the same record (though with far fewer knockouts) sported by the late Rocky Marciano when he retired as heavyweight champion of the world 60 years ago this month.

However, Marciano only fought for eight years, retired at 32 and even with a perfect record is hardly in the conversation of the best heavyweights of all time, never mind among all fighters. 

For better or worse, Mayweather belongs in the conversation of the greatest fighters in boxing history. No, he's not the best ever, despite his "TBE" marketing campaign over the past few years. 

He is, however, the richest fighter ever, having set all box office records in his May '07 win over Oscar de la Hoya and then twice breaking his own records. Wins over Saul 'Canelo' Alvarez (Sept. '13) and Pacquiao were far more lucrative than historic, though both play a major part in definining 19 years of greatness, including 17 years spent either at the championship level, as the best fighter in the world, or for the past several years of his career, both. 

Now, he insists, it's all over.

"You got to know when to hang it up," Mayweather said of the decision to make this his last-ever fight. "I'm knocking at the door of 40 years old. 19 years, 18 years as champ (actually 17, with his first championship won in 1998).

"I'm leaving the sport with all my faculties. I'm still sharp, I'm still smart."

And still undefeated, and the very best fighter in the world. 

UNDERCARD WORTH PRICE OF ADMISSION

While there was enormous backlash over a mismatch like Mayweather-Berto coming with an asking price of $64.95 (plus $10 for HD) to watch on Pay-Per-View, those who bit down and ordered were given their money's worth with a loaded undercard.

The evening's chief support was a rematch to one of the best fights of 2015, between Roman Martinez and Orlando Salido. The super featherweights somehow managed to outdo the original, going to war for 12 taxing rounds, only for the slugfest to end in a three-way stalemate. 

Scores were 115-113 Salido, 115-113 Martinez and 114-114 even. Most observers had Salido winning the fight, although this particular reporter was content with the draw verdict. 

Martinez dropped Salido twice in their first fight, in which he claimed a unanimous decision to begin his third reign as a super featherweight titlist. This time both fighters hit the deck, each in a wild round three. 

They managed to outdo that frame with a free-swinging 10th round that saw Martinez recover from a mid-rounds slump to go toe-to-toe with Salido, who at age 34 and now 19 years as a pro looked reborn after coming out to a deliberate start. The former two-division champ threw well over 1,000 punches, landing over 100 more than Martinez, who rallied late to pull out the three-way draw. 

Also highly entertaining were the PPV prelims. 

Badou Jack rode an opening round knockdown and second half surge to score a well-earned split decision over mandatory challenger George Groves in their super middleweight title fight. 

The win marked the first successful defense of the title Jack claimed in a majority decision win over previously unbeaten Anthony Dirrell in April. It also marked his second victory of 2015 in fights where he came in as the underdog versus perennial Top 10 super middleweights. 

Groves came up empty in his third bid at a major title. His previous two shots resulted in knockout losses to Carl Froch, with each title fight serving as the lone three losses on the Brit's professional record. 

Opening the PPV portion of the show, Jonathan Oquendo recovered from an opening round knockdown to return the favor one round later en route to a shocking 10-round win over former two-division champ Jhonny Gonzalez. Scores were 94-94 even, 95-93 Oquendo and a "say what?" 98-90 tally from Robert Hoyle also in favor of Oquendo. 

Hoyle gave Lisa Giampa a good run for the worst scorecards of the night. Vanes Martirosyan was forced to settle for a 10-round majority decision over former 154 lb. champ Ishe Smith in a super welterweight bout that aired on Showtime as part of its "free-view" special preceding the PPV event. 

Martirosyan scored knockdowns in rounds three and eight, neither of which were deemed worthy of a 10-8 round in Giampa's blurry eyes. Both frames were scored 10-9, leaving her with a 95-95 tally. Matching scores of 97-91 granted Martirosyan a well-earned win, rebounding from a debatable 10-round loss to Jermell Charlo earlier this year. 

Jake Donovan is the managing editor of BoxingScene.com.
Twitter: @JakeNDaBox
Facebook Page: JakeBScene