* Rose signs off with 66 to seal one-shot win
* American Tringale finishes alone in second (Adds detail, quotes)
April 26 (Reuters) - England's Justin Rose held off a string of challengers with a clutch birdie-birdie finish to win his seventh PGA Tour title by one shot at the weather-disrupted Zurich Classic of New Orleans in Avondale, Louisiana on Sunday.
Tied for the lead when the delayed third round was completed earlier on a marathon day at the TPC Louisiana, Rose closed with a flawless six-under-par 66 on a receptive, rain-softened layout where preferred lies were permitted throughout the tournament.
The world number nine, a runner-up at this month's Masters, posted a 22-under total of 266, then waited for the last few groups to finish before he could celebrate his victory.
"It's an event I have played many times and I feel like, year-on-year, I've been getting closer and closer (to winning)," a smiling Rose, who is an official ambassador for the tournament sponsor, told CBS Sports.
"I always joke with the Zurich guys that this is my fifth major. Any win is sweet but when you get to share it with people that you are close to, it's fantastic."
Cameron Tringale, one of five players who held at least a share of the lead in the final round, eagled the par-five seventh on the way to a 65 and second place at 21 under, ending up a stroke in front of fellow American Boo Weekley (65).
Australian world number six Jason Day, the highest-ranked player in the field who shared the 54-hole lead with Rose, signed off with a 69 to tie for fourth at 19 under with American Jim Herman (65).
As expected, the final round turned out to be a slug-fest with conditions ideal for low scoring.
Rose edged one stroke clear of a tightly bunched leaderboard with a timely birdie at the par-three 17th where he struck a five-iron from 210 yards to 10 feet, then coolly sank the putt before pumping his right fist in celebration.
He then drained a 14-footer to birdie the par-five 18th and punched his right arm skywards in delight.
"The golf course is yielding birdies ... and when you do miss the odd birdie putt, you feel like you're going backwards," said Rose.
"All week, I just kept trying to tell myself to stay patient. I missed a couple of shortish ones on 11 and 12 ... obviously to make those putts on the last two greens made up for everything." (Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry)