The defending champions made 300 for seven from their 50 overs after electing to bat.
Virat Kohli (107) and Shikhar Dhawan (73) shared a second-wicket stand of 129 before Suresh Raina hit 74 off 56 balls.
Sohail Khan starred for Pakistan with five for 55.
In reply, Pakistan were bowled out for 224 with skipper Misbah-ul-Haq making 76.
India have now won all six of their World Cup matches against Pakistan.