Mayweather was awarded the fight 118-110, 116-112 and 116-112 by the three judges.
The five-weight world champion is now undefeated in 48 professional fights, stretching back 19 years.
Meanwhile his opponent and six-weight world champion Pacquiao, who falls to 57 wins, six losses and two draws, later blamed a shoulder injury for his defeat.
Read more at BBC Sport | Photo: AP
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