American young gun Jordan Spieth won the 79th Masters in record-equalling style with a wire-to-wire victory, landing his first major title by four shots.

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.

World number four Spieth tied the previous best set by Tiger Woods when he clinched his maiden major title at the 1997 Masters.

Justin Rose of England, the 2013 US Open champion, 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.

McIlroy's 66 was only matches by Japan's Hideki Matsuyama whose six under round saw him finish fifth, one shot behind the world number one.

"It was very nerve wracking today," Spieth said after being helped into the coveted green jacket by last year's Masters champion, Bubba Watson.

"I didn't sleep last night. It's the most incredible week of my life and a dream come true for me."

Spieth, who led by four strokes overnight, never allowed his challengers to get any closer than three shots as he relied on his trusty putter and ice-cool composure to rebound from any stumble in breezy conditions.

Out in one-under 35 with a five-stroke cushion, he drained a 20-footer for birdie at the 10th to briefly forge six ahead before he faltered with a three-putt bogey at the tricky par-three 12th.

However, Spieth reached the green in two at the par-five 13th to card his fifth birdie of the day, and picked up another shot at the par-five 15th, again after two-putting, to keep at  bay Rose, who reeled off three straight birdies from the 13th.

At that point the first player ever to reach 19 under at the Masters, Spieth did well to save par at the 16th where he coolly knocked in an eight-footer.

After pushing his tee shot right into the trees at the par-four last, Spieth hit his second to just short of the green, chipped up to five feet but narrowly missed the par putt to slip back to 18 under.

Darren Clarke and Graeme McDowell finished well down the field with matching six over finishes.