Floyd Mayweather claimed a unanimous points verdict over Manny Pacquiao to win the richest fight in boxing history and maintain his perfect record.
Mayweather, unbeaten in 48 professional fights stretching back to 1996, retains his WBC and WBA welterweight titles and takes the WBO belt from Pacquiao.
The American was caught with the odd good shot, but was quicker throughout and always looked in control.
At a 16,000 sell-out MGM Grand Garden Arena in Las Vegas - where some spectators had paid as much as $350,000 for tickets on the resale market - Mayweather, 38, started much the better of the two fighters.
Mayweather bossed the early rounds before Filipino Pacquiao had success in the fourth with a couple of strong left hooks to the head.
But the American always dominated and largely stayed out of trouble, keeping Pacquiao at arms length with his superior footwork.
Noisily backed by the 16,000-strong crowd, Pacquiao, 36, continued to have the odd success - landing a strong left in the eighth - but Mayweather's speed and movement proved key, and as the fight wore on he began to have more success.
The 11th was the most one-sided of the contest as Mayweather, looking as fresh as he had in the opening round, picked off a tired-looking Pacquiao almost at will.
Mayweather avoided Pacquiao's increasingly ragged attempts to land in the final round and comfortably won on all the judges' scorecards.
The fight, watched by celebrities and sporting stars, is expected to generate an estimated $400m (£265m).