|Genesis Open first-round leaderboard|
|-7 S Saunders (US); - 5 D Johnson, JT Poston, B Stegmaier, D Summerhays (US), C Percy (Aus)|
|Selected others -4 P Harrington (Ire), P Mickelson (US); -3 L Donald (Eng); -2 J Rose, P Casey (Eng), G McDowell (NI); -1 M Laird (Sco); Level J Day (Aus)|
Dustin Johnson's bid to overtake Jason Day as world number one continued with a first-round five-under par 66 at the weather-interrupted Genesis Open.
Johnson trails fellow American Sam Saunders by two shots for the lead, and can overtake Day with victory if the Australian ties for third or worse.
Day is tied for 74th on even par after only 16 holes, as play was suspended because of darkness in California.
Johnson, starting on the back nine, birdied the 11th, 14th, 17th and 18th.
He was stung by a bee on the first hole and hit his only bogey on the fourth, missing "a pretty easy par putt".
"It would be great to get number one but I'm focused on this week," he told the PGA Tour website.
"I played really solid all day long but I just want to put myself in a position to have a chance to win on Sunday. That's the only thing I'm really thinking about."