Stolz was 217th on the PGA Tour money list before the start of the tournament, but the $720,000 paycheck moved him to 89th. The victory also gives him multi-year status on tour.
'It was pretty awesome,' said Stolz, a Nationwide Tour veteran. 'Winning, it doesn't matter where you are, it's the same job, to beat the guy you're playing with.'
Ridings played the back nine first at the TPC at Summerlin, the host course for the final round after play rotated between Summerlin, Bear's Best and the TPC at The Canyons for the first three rounds. He fired an 11-under 61, while Frazar posted a 67 and Lehman birdied the last en route to a 3-under 69 on Sunday.
Dicky Pride bogeyed the last when his drive went in a hazard. That gave him a final-round 69, which tied him for fifth place with Carl Pettersson (67) at 19-under-par 268.
Stolz trailed Lehman by a stroke after the third round, but birdied the first and used some spectacular iron play to get into first. He spun approaches to 3 feet to set up birdies at six and seven, then ran home an 8-footer for birdie at the ninth to reach 20 under par and take sole possession of the lead.
Meanwhile, players not near Stolz on the course, were making up ground on the leaderboard. Ridings started on the second nine and recorded four birdies, but his play on the front nine had him flirting with golf's magic number of 59.
He made a 75-foot birdie from off the putting surface at two, then birdied five of his next six holes. Ridings knocked his approach to 4 feet at the ninth and made the putt to get in the clubhouse at 20 under par.
'I really thought it would have to be 59 to get up there,' said Ridings. 'Next thing I know, I start making some putts and I birdied the last four holes. It was under the radar as far as I was concerned.'
Frazar, who lost in a playoff to Ernie Els at the Sony Open in Hawaii, appeared to be out of it with a bogey at the 10th, but he two-putted from 40 feet for birdie at the par-5 13th, and added a pair of birdies at 15 and 16 to join Ridings in the clubhouse at minus-20.
Stolz was tied for the lead with that duo, but Lehman made some noise on the par-5 16th. His second landed 18 feet past the hole and the 1996 British Open champion sank the eagle putt to join the leaders at 20 under par.
Stolz hit a 9-iron over the green at No. 16, and his chip stopped 7 feet short of the hole. The Australian stroked home the birdie putt to go one ahead.
At the 17th, Lehman hit a terrible tee ball that landed right of the green, and his second stopped 5 feet from the cup. His par-saving putt lipped out so Lehman fell two off the lead.
Stolz, who played with Lehman and was last to go on the 17th tee, hit a 6-iron 35 feet right of the hole and two-putted for par. That tee shot might have sealed the victory because with Lehman and Dicky Pride, the third member of the group, both right of the putting surface and water on the left, Stolz hit it in the perfect spot.
'That was a great shot,' said Stolz, referring to the 6-iron at 17. 'It's one of those shots that you've got to suck it up and hit a great shot. I hit a horrible shot there yesterday, so it was good to clear those ugly thoughts out.'
Stolz found the fairway off the 18th tee, but hit his approach 45 feet right of the target. His birdie try came up 4 feet short, but Stolz sank the par putt for his first win.
David Frost also played the back nine first and he fired a 10-under 62. He shared seventh place with two-time U.S. Open champion Lee Janzen (65), Danny Ellis (63) and Tim Petrovic (69) at 18-under-par 269.