Four strokes ahead going into the final round at Augusta National, the 21-year-old Texan closed with a two-under-par 70 to match the tournament record low of 18-under 270 for 72 holes.
Spieth equalled the previous best set by Tiger Woods when he clinched his maiden major title at the 1997 Masters.
Justin Rose signed off with a 70 to share second place with three-times winner Phil Mickelson, who carded a 69.
Rory McIlroy was best of the Irish contingent and finished fourth on 12 under par after shooting the lowest round of the day, a 67.
Darren Clarke finished seven over while Graeme McDowell was nine over.
McIlroy was able to draw many positives from the round despite not being able to complete the grand slam……