LAS VEGAS, Oct 7, 2012 (AFP) - Moore, who lives in Las Vegas, won by one stroke, setting a tournament 72-hole scoring record with a 24-under 260 total.
"It is unbelievable," Moore said, whose wife is expecting a child in 25 days.
"The countdown starts here. That is it for me; I am done for the year."
Moore bettered fellow American Kevin Na's previous record of 261 which Na established in 2011.
Zimbabwe's Brendon de Jonge closed with a four-under 67 to take second at minus-23 at TPC at Summerlin. De Jonge shared the third round lead with Moore and Sweden's Jonas Blixt.
Moore rolled in a birdie on the 16th hole to take the outright lead. He said the support he received from family and friends this week helped motivate him.
"I got 35 to 40 people here with me so this week is real special," he said. "I got such great people around me."
Moore collected $810,000 in first place prize money in the Fall Series opener.
Blixt posted a 70 to finish in sole possession of third at 20-under-par 264.
Aussie Jason Day fired a seven-under 28 on the front nine, but double-bogeyed the 18th hole to shoot 65.
He placed fourth at minus-18, while Bill Lunde shot 66 to end by himself in fifth at 15-under 269.
Day, of Brisbane, pulled within three shots of Moore and de Jonge with a birdie on the No. 16 but then ran into trouble on 18.
Leading scores on Sunday after the fourth round of the $4.5 million US PGA Justin Timberlake Shriners Hospitals for Children Open (par-71, USA unless noted):
260 - Ryan Moore 61-68-65-66
261 - Brendon de Jonge (ZIM) 62-66-66-67
264 - Jonas Blixt (SWE) 64-64-66-70
266 - Jason Day (AUS) 69-68-64-65
269 - Bill Lunde 67-69-67-66
270 - Richard H. Lee 66-68-71-65, Scott Piercy 67-66-73-64
271 - Blake Adams 65-70-68-68, Jason Bohn 71-66-64-70
272 - Tim Herron 63-68-68-73, Jimmy Walker 67-66-66-73, Nick Watney 66-66-71-69
273 - Bobby Gates 70-67-66-70, Mathew Goggin (AUS) 68-69-70-66, John Huh 63-69-72-69, Colt Knost 68-67-66-72, Russell Knox (SCO) 66-67-68-72, Jeff Overton 70-66-68-69, Heath Slocum 67-67-74-65, Brendan Steele 69-67-70-67, Michael Thompson 70-66-68-69