Former Masters champion Patrick Reed didn't put a foot wrong on the North Course at Torrey Pines Thursday, firing an eight-under-par 64 to share the first-round lead in the PGA Tour Farmers Insurance Open with Sweden's Alex Noren.

Reed opened with three straight birdies at the 10th, 11th and 12th and added one more at 17 to make the turn at four-under.

His four birdies coming in included another three in a row at the fifth, sixth and seventh.

"It felt easy out there, just kind of with how I was hitting the driver, getting the ball in the fairway," said Reed, the world number 11 who is coming off a missed cut at La Quinta, California, last week.

"I was able to hit the draws, hit the fades. The hardest, longest chance I had was on four today, had a 35-footer for birdie and hit a great first putt, missed it three feet to the right and had a three-footer, but that's about it ... everything else was pretty easy."

Noren, a 10-time winner on the European Tour who is still chasing a first US PGA Tour title, also played the North Course, which played much easier than the South Course that will host the US Open in June.

Noren -- who fell to Jason Day in a six-hole playoff at Torrey Pines in 2018 -- had an eagle and seven birdies with just one bogey in his eight-under effort.

"I hit it very good with my irons and wedges, putted very good," said Noren, who rolled in a 20-foot eagle putt at the 17th.

The leading duo were one stroke in front of reigning Rookie of the Year Scottie Scheffler, whose seven-under 65 on the North Course included holing out for an eagle two at the par-four 16th.

Peter Malnati and Ryan Palmer notched the best score of the day on the South Course, joining a group of 12 players on 66 that also included former US Open champion Gary Woodland, South Korean veteran K.J. Choi, Australians Rhein Gibson and Cameron Smith and Americans Beau Hossler, Talor Gooch, Luke List, Sam Burns, Lanto Griffin and Brandon Hagy.

McIlroy charge stalls

On the South Course, Northern Ireland's Rory McIlroy, who was four-under through nine holes but even par with a bogey and a birdie coming in for his four-under 68.

"A little disappointed I didn't pick up a couple more on the way in, especially with the two par fives, not picking up any shots there," McIlroy said, but added: "I think anytime you shoot 68 on the South Course here you've got to be pretty happy."

Lucas Glover also carded a 68 on the South Course, where world number two Jon Rahm of Spain had six birdies and three bogeys in his three-under 69, defending champion Marc Leishman of Australia posted a 71 and former world number one Brooks Koepka fired an even par 72.

Things looked likely to be tougher on both courses on Friday, with a heavy rain expected to move in overnight after a day of breezy sunshine.

Reed said the grim forecast was on his mind as he sought to "make as many birdies as possible to be able to kind of weather the storm tomorrow."