* Moore holds off last-day challenge by de Jonge
* Clinches second PGA Tour title by one shot (Adds detail, quotes)
Oct 7 (Reuters) - American Ryan Moore, rock-solid over the closing stretch, fended off playing partner Brendon de Jonge of Zimbabwe in a final-round duel to win his second PGA Tour title by one shot at the $4.5 million Las Vegas Open on Sunday.
Tied for the lead overnight with de Jonge and Swede Jonas Blixt, Las Vegas resident Moore fired a five-under-par 66 in glorious afternoon sunshine at the TPC Summerlin to finish with a 24-under total of 260.
"It's been an unbelievable week," a jubilant Moore said on the 18th green after tapping in a short par putt there to clinch victory before thrusting his arms skywards in celebration.
"I have had such great support from a bunch of family and friends out here. When I won the Wyndham, there was actually nobody there with me and I've got about 35, 40 people with me this week."
Moore covered the back nine in a flawless three-under 33 to shake off de Jonge in what proved to be a two-man Sunday shootout in the Nevada desert, the Zimbabwean having to settle for a career-best second after closing with a 67.
PGA Tour rookie Blixt, like de Jonge seeking a maiden title on the U.S. circuit, carded a 70 to secure third place at 20 under, two strokes better than Australian Jason Day (65).
Moore, who claimed his first PGA Tour title at the 2009 Wyndham Championship, will have further cause to celebrate as his wife Nichole is scheduled to give birth to their first child in less than a month.
"We've got our first baby on the way in about 25 days, so the countdown starts right now," Moore beamed. "This is it for me (on the 2012 PGA Tour). I am done for the year."
Though three players had shared the lead overnight in the first of four events in the PGA Tour's Fall Series, Blixt slipped back with a bogey at the par-four first, effectively leaving Moore and de Jonge to duel for the title.
Moore birdied three of the first seven holes to move two strokes clear but then bogeyed the par-three eighth, where de Jonge holed a birdie putt from just off the edge of the green, to make it a two-way tie at the top at 20 under.
Moore and de Jonge carded matching birdies at the ninth, 11th and 13th to remain level, though the Zimbabwean squandered a golden chance to grab the outright lead when his six-foot birdie attempt on 12 slipped past the right edge of the cup.
The tournament was ultimately decided at the par-five 16th where Moore edged one stroke clear with a two-putt birdie after the longer hitting de Jonge had found trees off the tee and was forced to chip out sideways with his second shot.
"You've only got to get a ball on the fairway there and then you're going to be hitting a mid-iron in there today, it was playing a little bit down breeze," de Jonge said of his wayward drive at the 16th.
"That was definitely the turning point for me."
Both players parred the last two holes and de Jonge, who had previously finished third three times on the PGA Tour, had to settle for his first ever runner-up spot.
"I am obviously a little bit disappointed right now but, in saying that, Ryan played great all day," said the 32-year-old Zimbabwean. "He was very, very solid, especially down the stretch. He hit some great shots.
"I will build on that. Obviously it's disappointing but I'll get over it pretty quickly. It was fun out there." (Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)