Jordan Spieth focused on "boring golf" and shrugged off an unexpected birdie drought in the final round as he clinched his ninth PGA Tour victory, by four shots, at the AT&T Pebble Beach Pro-Am.
A commanding six strokes ahead overnight, the world number six carded a bogey-free two-under 70 on a picture-perfect afternoon of unbroken sunshine on the Monterey Peninsula.
"It's unbelievable," Spieth, 23, told CBS Sports after becoming the first player since Tiger Woods to win nine times on the PGA Tour before the age of 24.
"Today I hit 17 greens, it was kind of a dream round for ball-striking when you are leading by a bunch and I finally got one (a birdie putt) to go on 17.
"Boring golf," double major champion Spieth said with a smile after totalling 33 putts on Sunday compared to 23 the previous day.
"I apologise but that was kind of the game plan. That's what was needed today and fortunately that's what we did to close it out.
"We could afford to make a couple of mistakes if I needed to ... fortunately we didn't and we just stayed ahead."
The Texan finished at 19-under 268, while fellow American Kelly Kraft, the 2011 U.S. amateur champion, fired a 67 for second place at 15-under, with compatriot American Dustin Johnson (68) a further stroke back.
New Zealand's Tim Wilkinson had a strong finish to his campaign at Pebble Beach, the left hander shot a final round two under 70 to finish four under overall.
Wilkinson finished in a tie for 39th, his third best finish of the new season so far.
Fellow New Zealander Steve Alker missed the cut by two shots while Danny Lee pulled out in the first round.