LOS ANGELES -- Getting around Riviera Country Club unscathed is no small task, which is what made Matt Kuchar's day all the more remarkable.
Kuchar drove to the edge of the 10th green and two-putted for birdie and kept right on rolling until he had a 7-under 64 on Thursday, matching his best score at Riviera and giving him a three-shot lead in the Genesis Invitational.
So clean was Kuchar's round that he only once had to stress over a par putt, and he made the 10-footer at the par-3 fourth.
"I think it's one of the few courses that has truly stood the test of time," Kuchar said. "It was a great test of golf 50 years ago when Ben Hogan was playing; it's a great test today with Tiger Woods and all the young boys playing."
The conditions were ideal once the morning chill gave way to mild sunshine, and Kuchar took advantage in the morning. As much as Kuchar loves the course, he has only one top-10 in his 13 previous appearances.
Woods was 4 under through eight holes and had to settle for a 69.
With the death of Lakers icon Kobe Bryant, his daughter Gianna and seven others in a helicopter crash on Jan. 26 still raw in Los Angeles, the tour dedicated No. 8 -- Bryant wore Nos. 8 and 24 during his 20 years with the Lakers -- with a purple-and-gold tee sign.
Brooks Koepka had Nike design some purple-and-gold Mamba golf shoes last October because Bryant inspired him during his return from injury. Koepka called the shoe company after hearing of Bryant's death and suggested something be done, oblivious that he had requested the shoes months earlier. He opened with a 69.
Justin Thomas, who auctioned off Kobe-themed sand wedges that he used in the Phoenix Open, had FootJoys of purple and gold. They didn't help him much on this day. He opened with a 74 and was in danger of missing the cut for the second time this year.
Kuchar made birdie on two of the par 5s, made two birdie putts of 30 feet or longer and rarely was in trouble.
"To shoot a number like this, you kind of do most things well," Kuchar said. "I didn't find myself in much trouble today. ... I felt like it was just steady golf, a lot of opportunities, and I was able to convert on a good number of opportunities today."
K.H. Lee and Russell Henley also played bogey-free and were at 67, along with Wyndham Clark from the morning wave. Adam Schenk and Harold Varner III each had 67 in the afternoon under a little more breeze and on greens that were bumpier from so much foot traffic during the day.
Rory McIlroy opened with a 68 in his return to No. 1 in the world, and it took him time to get going.
McIlroy's opening tee shot was pure enough, but it bounced over the 10th green and rolled up near the lip of a back bunker. He left his first shot in the sand and did well to escape with par, only to miss 3-foot putts on the next two holes -- one for birdie, one for par.
He had to scramble his way along the back until blasting a 3-wood to about 30 feet on the par-5 17th and making eagle, and then adding an eagle on par-5 opening hole.
The biggest challenge was the cold air in the morning.
McIlroy ripped a drive -- he did that a lot in the opening round -- into the par-5 11th and then came up 30 yards short with a flush 3-wood. About two hours later, he had 289 yards for his second into the par-5 17th and hit 3-wood to pin-high.
"It just shows you what temperature does," McIlroy said.
Even in mint conditions, only about one-third of the field broke par.
Information from The Associated Press was used in this report.