Floyd Mayweather was named winner by unanimous decision in a 12 round boxing match against Manny Pacquiao. (Reuters)

After more than five years of squabbling, eight weeks of training and 12 rounds of fighting, it came down to this: a few tense minutes awaiting the judge’s scorecards. Manny Pacquiao circled the ring and blew kisses to the crowd. Floyd Mayweather jumped on the ropes and defiantly barked at no one in particular. He knew he’d won the bout and secured his legacy, but everyone else needed judges’ confirmation.

Moments later, the scorecards made it official: Mayweather’s perfect record would remain intact, the best fighter of his generation had finally received the confirmation so many had demanded, and Pacquiao, the passionate boxer from the Philippines, would head home wrestling with both disappointment and confusion over the result.

Neither fighter offered many surprises. Mayweather was at his defensive best, and Pacquiao kept charging ahead like a bull charging a cape. Judge Glenn Feldman scored the bout 116-112, Bert Clements had it 116-112 and Dave Moretti saw it 118-110, all in favor of Mayweather, who improved his record to 48-0.

“I did my best. But my best wasn’t good enough,” said Pacquiao, who was surprised by the judges’ decision.

It was the biggest event boxing has staged in years, generating huge hype around the world, surely shattering records for live gate and pay-per-view buys and filling the MGM Grand Garden Arena with a who’s who of celebrities, including Clint Eastwood, Denzel Washington, Michael Jordan, Tom Brady and so many others. It will go down as the richest bout in the sport’s history, though not necessarily the most exciting.

The showdown was years in the making, as both camps continuously bickered and at times the boxing world seemed certain the two might never square off. Fans were forced to wait even longer Saturday night, as cable services nationwide were overwhelmed with pay-per-view orders. Promoters delayed the start of the fight and the opening bell didn’t ring until 11:58 p.m. Eastern time.

“When the history book is written, it was worth the wait,” Mayweather said after the bout.

Pacquiao said he fought Saturday with a right shoulder injury, a muscle tear that he suffered in training camp about three weeks ago. He was denied a shot of a numbing medication by the Nevada Athletic Commission prior to the bout.

Hours before stepping into the ring, Pacquiao was in good spirits. He was with more than 50 family members and friends back at the hotel, dining on steamed fish and white rice while chatting with several pastors. They had a spirited discussion about one of the first documented fights: David vs. Goliath. Pacquiao left the hotel, arrived at the MGM Grand shortly after 6 p.m. local time and four hours later confronted a giant of his own.

Pacquiao was active much of the night and pushed Mayweather to the ropes, the likely game plan for both fighters. As he does better than anyone, Mayweather constantly baited his foe, using his speed to fire laser-quick counters.

Pacquiao, meanwhile, struggled to connect. He landed just 18 jabs on the night. The two fighters threw about the same number of punches — 435 for Mayweather and 429 for Pacquiao — but Mayweather landed 148 to Pacquiao’s 81. At one point, Mayweather made a show of shaking his head “no,” telling Pacquiao that his punches were being blocked and doing no damage.

The judges each gave Mayweather the first three rounds. Pacquiao unleashed his first real flurry midway through the fourth, punctuating a string of blocked shots with a clean hard left to Mayweather’s face. In his corner, Mayweather’s trainer, Floyd Mayweather Sr., barked at his son to be more aggressive.

By the late rounds, Mayweather looked more comfortable, dancing around the perimeter, dictating the fight on his terms. They settled into a fight-night two-step: Pacquiao would charge, and Mayweather would counter. Pacquiao would attack, and Mayweather would score.

“He’s a hell of a fighter. I take my hat off to him,” Mayweather said. “Now I see why he’s one of the guys who’s at the pinnacle of the sport of boxing.”

The loss was Pacquiao’s third in his last six outings. His record falls to 57-6-2. The Filipino fighter entered the ring with the hopes of an entire nation on his shoulder, and inside the arena, too, much of the sell-out crowd of 16,507 fight fans were loud and raucous in their support of Pacquiao.

What they saw was a clinic in the so-called sweet science. Even at 38, Mayweather showed why he’s one of the best defensive fighters the sport has seen. He blocked, ducked and clutched, baiting Pacquiao and using his reach advantage to counter with snappy jabs.

The methodical bout might not go down as one of the sport’s classics, but the win will go a long way toward defining Mayweather’s legacy. He kept the perfect record in tact, but more importantly, he finally vanquished the only other fighter who could challenge him in either popularity or boxing skill. Mayweather had posted wins over the likes of Oscar De La Hoya, Shane Mosley, Miguel Cotto, Ricky Hatton and Zab Judah, but until Saturday his résumé was noteworthy for what was missing: Pacquiao's name.

Mayweather, of course, already considered himself a part of boxing royalty, calling himself TBE – “the best ever” – and saying he’s as successful as Muhammad Ali. And that was before beating Pacquiao so handily. Mayweather long ago made a name for himself as the sport’s resident peacock, undisputed and undefeated when it comes to bluster, confidence and ego. But he was refreshingly subdued in the weeks leading up to the Pacquiao bout, saying he’d matured and was content to let his unmatched boxing ability do the talking.

Still, when critics debate Mayweather’s place among the all-time greats, they’ll note that he often faced his toughest competitors once they were past their prime. Pacquiao, for example, is 36 and showed again Saturday night that he’s not quite the same explosive fighter who posted thrilling wins over Cotto, Hatton and De La Hoya a half-dozen years ago.

Imperfect outside the ring — a series of domestic violence charges and accusations have made him pariah to many — Mayweather remains perfect inside it. The strong betting favorite entering the fight, he already held the WBA and WBC welterweight belts and left the arena Saturday night with Pacquiao’s WBO title, too.

The big win could mark one of the last times Mayweather sets foot in the ring. He has one fight remaining on his deal with Showtime and says he’s inclined to hang up his gloves after fulfilling his contract with a bout in September. Mayweather hasn’t mentioned any potential opponents for that date. Before either fighter set foot in the ring Saturday night, both camps seemed to think a rematch was unlikely.

Then again, for years it seemed like meeting just once was also unlikely — until the money became too much to ignore. Revenues from Saturday’s fight were expected to reach $300 million, and Mayweather alone could pocket as much as $200 million for 12 rounds of work.

While fans around the world paid $100 apiece to watch on pay-per-view, the inside of the MGM Grand Garden Arena was largely high rollers. The tickets carried a face value of $1,500 to $10,000 but sold for much more on the secondary market.