Los Angeles - Americans Andrew Landry and Scottie Scheffler pulled away with birdie binges to share a four-stroke lead after Saturday's third round of the PGA Tour's American Express tournament.

Landry birdied six of his first eight holes on the way to a seven-under 65 at the PGA West Nicklaus course while Scheffler shot a bogey-free six-under 66 at the PGA West Stadium course to finish on 21-under 195 after 54 holes.

Compatriot Rickie Fowler, who shared a one-shot lead with Scheffler over Landry after 36 holes, was third on 199 after a 70 on the stadium course to join the co-leaders in Sunday's final group.

The first three rounds were played on three different layouts in the desert at La Quinta, California - also including the La Quinta Country Club.

Sunday's last round will be played on the Stadium layout where Scheffler shined, rolling in a six-foot birdie putt at the second, a 14-footer at the par-3 fourth and a seven-footer to birdie the par-5 fifth.

"It's a tough course," he said.

"It's a good tract and a good test."

Scheffler birdied the par-5 11th then hit back-to-back birdies at the 14th from 21 feet and at the par-4 15th when his approach landed inches from the cup.

Now the 23-year-old rookie from Dallas takes aim at his first PGA title after two developmental tour wins last year.

"Winning is pretty similar at all levels of the game and I've done a good job of closing them out," said Scheffler. "It should be a fun day and hopefully a rewarding one."

Landry, a 32-year-old Texan from Austin, made a sizzling start on the back nine, added back-to-back birdies at the fourth and fifth holes and took his lone bogey at the par-3 eighth.

"I've been putting the ball absolutely beautifully," Landry said.

"The wedges are there. The putting is there. Just need to go out and do it again tomorrow."

Landry's lone PGA title came at the 2018 Texas Open.

"You've got to really stay patient and keep playing and you never know what can happen," Landry said.

"I'm just going to go out tomorrow and have fun and see what happens."

Fowler had early setbacks with bogeys at the par-3 fourth and par-4 seventh holes but sank a 23-foot birdie putt to close the front nine, then sank birdie putts from inside seven feet at the 12th, 14th and par-5 16th to stay in the hunt.

"A couple of mental errors cost me," Fowler said.

"I struggled to get things going early.

"I did a good job of hanging around and not getting too far behind. I had to grind it out to put myself in position where I have a chance tomorrow to go after this."

Fowler's most recent of five PGA victories came at last year's Phoenix Open.

Americans Ryan Moore and Chase Seiffert shared fourth on 200.

Leading scores after Saturday's third round of the PGA American Express tournament, contested over the first three days at La Quinta (California) Country Club and the PGA West Stadium and Nicklaus courses (USA unless noted, par-72):

195 - Scottie Scheffler 65-64-66, Andrew Landry 66-64-65

199 - Rickie Fowler 65-64-70

200 - Ryan Moore 68-65-67, Chase Seiffert 66-67-67

201 - Andrew Putnam 67-69-65, Abraham Ancer (MEX) 68-67-66, Sebastian Cappelen (DEN) 67-70-64

202 - Tim Wilkinson (NZL) 71-65-66, Sepp Straka (AUT) 69-65-68, Tom Hoge 66-70-66, Alex Noren (SWE) 67-67-68, Im Sung-jae (KOR) 67-66-69, Brendon Todd 69-68-65, Wes Roach 68-65-69, Paul Casey (ENG) 68-67-67, Tony Finau 69-62-71, Hank Lebioda 65-71-66, Max Homa 71-68-63

203 - Harris English 71-68-64, Nick Watney 67-71-65, Brendan Steele 70-66-67, Bud Cauley 68-64-71, Adam Schenk 66-69-68, Sebastian Munoz (COL) 67-68-68, Brian Harman 67-67-69