But he remains unbeaten, 48-0, after turning Saturday night's Fight of the Century, with his usual incredible defensive skills and speedy footwork, into the best fight of May 2, 2015.
Boxing fans awaited this one for five years and, had they paid attention, they should have known better than to expect great action and huge punches landed. Mayweather simply cannot be hit.
Read the Los Angeles Times' special edition Flipboard digital magazine Mayweather vs. Pacquiao
He is the boxing-action cooler. Don't let him stand next to you at the craps table.
A large portion of the crowd, and those watching at home, undoubtedly were rooting for Mayweather to lose. Better yet, to get knocked out.
When you have various brushes with the law over domestic violence and like to send out pictures on the Internet of yourself, in bed surrounded by thousands of thousand-dollar bills, you find detractors quickly.
But Mayweather has never sought to win a popularity contest.
And he is so good at his craft that, Saturday night before the sold-out crowd of 16,507 in the MGM Grand Arena, the judges, Glenn Feldman, Burt Clements and Dave Moretti, accorded his exhibition of boxing skill a unanimous decision. Feldman and Clements had it 116-112, eight rounds to four, and Moretti had it 118-110, or 10 rounds to two.
"We did what we had to do tonight," Mayweather said, "and I'm truly blessed. I'm a calculated fighter, he's a tough competitor."
Pacquiao, one of the more agreeable athletes anywhere, uncharacteristically disagreed with the decision.
"I thought I hit him more times than he hit me," the Filipino congressman said. "I was very surprised at the score."
Pacquiao tried what so many other boxers have tried in the past — a relentless attack. If judges gave points for being the aggressor, Pacquiao would have been the unanimous winner. They obviously don't.
Mayweather has his own way of scoring points, with cobra-like counterpunching and similar jabs. The Compubox statistics had each throwing a similar number of punches (Mayweather 435, Pacquiao 429). But Mayweather landed 148 and Pacquiao 81.
The expectations for this fight, after a five-year wait and much back-and-forth controversy, were beyond high. Some ringside tickets reportedly brought as much as $350,000.
That prompted Jason Gay of the Wall Street Journal to muse in print, in the days before the fight, that as you pondered that, it gave you options.
"You have a choice. You can either buy a ticket to the fight," he wrote, "or buy a three-bedroom house for your mother."
Mayweather didn't mind the hoopla and hysteria.
"When the history books are written," he said, "this fight will be worth the wait."
That might not be the sentiment of many in the country who paid $100 for a pay-per-view showing. That price, in retrospect, probably didn't match the excitement of what happened in the ring.
In addition, the fight was delayed for more than a half an hour because cable carriers around the country — mainly Los Angeles favorite Time Warner Cable, plus Charter and Dish Network — were frozen by all the late attempts to purchase the pay-per-view showing.
One TV fight executive was asked why the cable carriers hadn't set a deadline for buyers early enough to avoid this situation.
"That's a great idea," he said.
Mayweather likes to wear caps that carry the initials TMT and TBE. That stands for The Money Team and The Best Ever. Humble he is not. Nor does he ever fail to both talk the talk and walk the walk. That 48-0 proves that.
He said afterward that he would fight one more time and retire at 49-0. Many feel it probably will go to 50-0 for a nice, round-number finish.
That last fight would be at the new 20,000-seat Anschutz Arena now being built between the New York New York and Monte Carlo casinos on the Strip. It will open about this time next year.
Mayweather said he expects to make as much as $200 million from this fight — that's assuming the cable companies got their act together and made the necessary sales.
It was a boxing match that turned this always-teeming city into a Rubik's Cube of humanity. Expectations ran high for an event that would join the likes of Ali-Foreman in boxing history.
It didn't quite get there, and that is thanks to the boxing style of Mayweather, who can take the air out of the balloon of even the hardest-punching, most-punishing fighter.
"He's is a hell of a fighter," Mayweather said of Pacquiao. "I take my hat off to him. Now I see why he is one of the guys at the pinnacle of the sport of boxing."
Mayweather meant "near" the pinnacle of boxing. At the top, there is room for only one, and after Saturday night, no further proof is needed.