Austin Cook takes lead in the desert with a 64 at La Quinta

It seemed like a minor adjustment, but it changed everything.

Ten months ago, Austin Cook had just missed his second cut in a row on the Web.com Tour, stalling in his effort to get to the major league circuit.

So, he changed his putting grip, simply moving his hands more closely together as he had earlier in his career. Over the next five months, he began making cuts, piling up top-10 finishes, and earned his PGA Tour card for the 2018 season.

Saturday in the third round of the CareerBuilder Challenge, Cook charged up the leaderboard with seven birdies and an eagle at La Quinta Country Club, shot an eight-under-par 64 — the best score of the day — and took a one-shot lead heading into Sunday’s final round at the PGA West Stadium Course. He is 19 under par.

“I missed a few putts early,” Cook said of Saturday’s round. “But starting on my fourth hole I was able to make a birdie and kind of get the ball rolling, and it never really stopped rolling.”

Second-round leader Andrew Landry, who shot a 70 on the Stadium Course, and Martin Piller, with a 67 at La Quinta, are a shot back at 18 under. Jon Rahm, whose errant tee shots led to three bogeys on the back nine, shot 70 and is tied at 17 under with Scott Piercy, who had a 66. They both played the Stadium Course, which has been a couple of strokes harder than La Quinta or the Nicklaus Stadium Course, and was that much more difficult Saturday when the wind became a factor for the first time this week.

“I knew I needed to take advantage today,” Cook said. “I was looking for six under or better, and I was able to get to eight…. I know that I wouldn’t have wanted to play the Stadium today.”

Andrew Landry plays his shot on the first fairway during the third round of the CareerBuilder Challenge at the TPC Stadium Course at PGA West on Saturday.

(Robert Laberge / Getty Images )

Piercy’s 66 was easily the best score on the Stadium Course, which is more susceptible to wind and more penal than the other two courses.

“I controlled my ball really well today,” said Piercy, a 39-year-old who has won three times on tour, most recently in 2015.

Rahm had four bogeys and six birdies in his round, which he called “a little bit of a survival day.”

How much of a factor was the wind? “Huge,” he said. “This is by far the hardest course of the three, the narrowest one, the one where you need to be more precise.”

Cook got his first PGA Tour win last fall in the RSM Classic in Georgia, in the early portion of the tour’s split schedule. He believes that experience will help heading into Sunday’s final round.

“I think tonight the nerves, the butterflies, all that will be less,” he said. “I think it would be a little different if I didn’t play like I did on Sunday at Sea Island, but I feel like I’m in a comfortable spot right now.”

Adam Hadwin played La Quinta in the third round for the second year in a row. He shot 59 there a year ago before winding up second. He didn’t threaten that score this time, but birdied three of his last four holes to shoot a respectable 67. That kept him in the hunt, three behind Cook. He’s tied with Grayson Murray and Brandon Harkins at 16 under.

The leaderboard is top-heavy, with 17 players within five shots of Cook. Saturday’s cut was at eight under par.

Phil Mickelson’s indifferent game continued Saturday. He had two bogeys in his first six holes on the Stadium Course, shot a 74 and missed the cut by four shots.

The challenges of the PGA Tour finally caught up to young amateur Charlie Reiter, the 18-year-old senior at Palm Desert High who had shot 68-70 in the opening two rounds. Reiter, who has committed to play at USC, double-bogeyed three consecutive holes in his first five on the Stadium Course and wound up with a 77 to miss the cut by seven shots.

John Daly had the kind of get-me-off-the-course round that always makes him a gamble as a sponsor’s exemption. Four under after two rounds, he ended his tournament by nonchalanting his way to an 80 at La Quinta.

Cook, Landry and Piller, all three graduates of the 2017 Web.com Tour, will play together in Sunday’s final group.

sports@latimes.com