LOS ANGELES (AFP) -- Zach Johnson, eager to focus on his game after the demands of Ryder Cup captaincy, fired a 10-under par 62 on Thursday, Jan. 18, to share the lead in the US PGA Tour American Express tournament with Sweden's Alex Noren.

Two-time major winner Johnson had 10 birdies on the La Quinta course, one of three in use over the first three days of the tournament in the California desert east of Los Angeles.

After stringing together six straight birdies from the fourth through the ninth, Johnson rolled in an eight-foot putt for his final birdie of the day at the 17th to take the solo lead.

Noren joined him after a more up-and-down day at La Quinta, where he was seven-under after his first seven holes thanks to five birdies and an eagle, then hit out of bounds to take a double bogey at his eighth hole, the par-four 17th.

Five birdies coming in, including two to cap his round at the eighth and ninth, pushed him to a share of the lead in pursuit of a first US tour title to go with his 10 European Tour victories.

Johnson, the 2007 Masters champion who claimed the last of his 12 tour titles at the 2015 British Open, missed the cut last week in Hawaii. But he said he was excited by the prospect of a season more focused on his game.

"Put a lot of good work in as of late," said Johnson, whose US team fell to Europe in Rome in last year's Ryder Cup.

"Actually been a lot of normal golf work, given what happened last year with what I was responsible for, which was awesome. Now it's time to get back to work. I've enjoyed the work. I've enjoyed the sweat."

Johnson said his day at low-scoring La Quinta was pretty straightforward.

"Got off to a good start. Gained some momentum. Hit a lot of shots in the middle of the club face. When I had loft in my hand I was able to be aggressive, which is always key. Obviously, I putted good."

Noren, meanwhile, had a sense of whiplash but was pleased with the ultimate outcome.

"I don't think I've been seven-under after seven, and then I hit it out of bounds on my eighth hole," he said. "Played a little worse in the middle ... Then came down with five birdies on the last, I don't know, six. So I'm super happy."

The leading duo were one stroke clear of Rico Hoey and Christiaan Bezuidenhout.

South Africa's Bezuidenhout had nine birdies in his nine-under 63 at La Quinta, while Hoey, who was born in the Philippines but grew up in southern California, had nine birdies in his 63 at PGA West.

Another nine players were tied on 64, a group that included world number five Xander Schauffele and sixth-ranked Patrick Cantlay. Of that group, Scott Stallings and Hayden Springer notched their eight-under efforts on the tougher Stadium Course, which will host the final round on Sunday.