With a final-round 69, Singh completed the tournament on 16-under-par 272, three strokes in front of Jeff Maggert.
Phil Mickelson finished alone in third place a further shot back.
Canada's Mike Weir, South Korea's K.J. Choi and third-round joint-leader Arron Oberholser tied for fourth on 279.
Singh, who earned $954,000 for the victory, extended his streak of top-10 finishes to 12 tournaments dating back last August's WGC-NEC invitational.
Jack Nicklaus holds the PGA Tour record of 14, a mark set in 1977.
The Fijian has three victories and six other top-five finishes in the streak, is a combined 146-under-par and $5,016,683 richer.
Singh has already earned $1,966,000 in the 2004 season.
"I'm playing pretty good," Singh said.
"I'm more concerned with how I'm playing week-in and week-out. I want to be number one before I finish, but it's hard to take Tiger (Woods) off the top."
Singh gets his shot at Woods in the Buick Invitational on Thursday.
EARLY TROUBLE
Joint-leader overnight, Singh cruised the front nine at Pebble Beach Golf Links in three-under 33 and his challengers quickly began to fall away.
Oberholser was even-par through eight holes with one bogey and one birdie, but a double-bogey six at the eighth took him out of the running.
The British pair of Phillip Price and Luke Donald, tied for third with Maggert and three strokes behind Singh and Oberholser when the final round began, encountered early trouble.
Price bogeyed the first hole and then the fifth on his way to a five-over 77. Donald bogeyed the second, then the fourth through the sixth and could only match Price's score.
Mickelson, four shots off the lead after 54 holes, also found problems early when he made bogey at the par-five second. He carded another bogey and two birdies on the front nine.
When Singh chipped in for birdie at the 10th, Mickelson had fallen eight shots off the pace.
His three birdies coming home moved him up the leaderboard, but Singh was all but uncatchable.
Maggert remained in the hunt the longest.
He carded three birdies against a lone bogey on the front nine, but when Singh birdied the 10th he had fallen five strokes adrift.
A birdie at the 13th pulled Maggert within four, but his unlikely bid to catch the leader ended when he four-putted the 16th for a double-bogey six.
Maggert did birdie the final two holes, however, to record his first top-10 finish since last season's Shell Houston Open.
The event was played over three courses with the field completing one round each at Spyglass and Poppy Hills and two, including the final 18 holes, at Pebble Beach.
