* Putnam and Petrovic set first-round pace
* Local amateur Pendrith opens with a 65 (Updates at end of round)
July 24 (Reuters) - Kyle Stanley has endured a frustrating 2013-14 PGA Tour season with 11 missed cuts in 25 starts but hinted at better things to come as he surged into contention for the Canadian Open in Montreal on Thursday before being overtaken late in the day by Michael Putnam and Tim Petrovic.
The 26-year-old American, whose short game has especially let him down this year, produced sparkling form with his putter as he racked up six birdies and a bogey in the opening round to shoot a five-under-par 65 on Royal Montreal's Blue Course.
Though Stanley failed to maintain momentum on his homeward nine after racing to the turn in an electrifying five-under 30, he ended a glorious, sun-splashed day one stroke off the pace set by his compatriots Putnam and Petrovic.
Putnam, a journeyman who has bounced between the PGA Tour and the lower-tier circuits over the past decade, got to six under with four birdies in his last four holes.
He was joined at the top late in the day by Tour veteran Petrovic, who eagled the par-five 12th on the way to a bogey-free 64 at the oldest golf club in North America.
Stanley, whose only PGA Tour victory came at the 2012 Phoenix Open, was thrilled to see significant improvement in his game around and on the greens after toiling for much of this season.
"I had some nice sand saves to keep the momentum and just kind of kept building on the round," Stanley told PGA Tour Radio after ending the round level with Canadian amateur Taylor Pendrith.
"I've struggled with my short game this year, especially with my putting, so it's nice to see the improvement there.
"It's been a pretty long year so far but I had a nice week off last week, went home to Gig Harbor (in Washington) and kind of re-charged."
Stanley, whose best finish on the 2013-14 PGA Tour was a tie for 19th at the CIMB Classic in October, made a sizzling start to his round after teeing off at the par-four 10th with three birdies in his first five holes.
He then drained putts from 20 feet at the 15th and from 23 feet at the 17th to surge to the top of the leaderboard, before offsetting a bogey at the third with a birdie at the sixth to remain at five under.
"I gave myself some opportunities and was able to make a couple of long-range putts which was nice," said Stanley. "I kind of hung in there on my second nine.
"I didn't hit it quite as well but was able to get it up and down when I needed to. It was nice to get off to a good start."
Some of the biggest roars of the day were directed at 23-year-old Canadian Pendrith, who mixed seven birdies with two bogeys to card a 65 in his first PGA Tour start.
"It was awesome," Pendrith, who won the 2013 Porter Cup and tied for fifth in the 2012 Canadian men's amateur championship, told Golf Channel. "I was just trying to play golf.
"I wasn't trying to worry about everything else going on. Obviously it can be a little nerve wracking the first time out here on Tour but after I played the first hole, I kind of felt calm and had a nice day.
"There weren't too many people following (his group) all day and then it just kind of seemed a lot more came for the last three or four holes," said the 23-year-old from Richmond Hill in Ontario, who birdied three of his last six holes.
A Canadian has not won the tournament since Pat Fletcher at Vancouver's Point Grey Golf and Country Club in 1954.
American Brandt Snedeker launched his title defence with a 69, the same score posted by his compatriot Matt Kuchar, the world number seven and the highest-ranked player in the field. (Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Steve Keating)