Rory McIlroy has failed to carry his Australian Open momentum into Tiger Woods' World Challenge tournament in California.
Four days after trumping Adam Scott at Royal Sydney's final hole to notch his first victory of the year, former world No.1 McIlroy battled to a one-over-par 73 to be six shots behind leader Zach Johnson.
Johnson got hot on a chilly day at the Sherwood Country club course at Thousand Oaks to amass seven birdies in his 67 and take a one-stroke lead from fellow American Matt Kuchar.
Tournament host Woods was four shots off the pace while Australia's Jason Day struggled to a 76 to be tied second last in the classy 18-man field for the non-official event.
Hunter Mahan and Bubba Watson shared third place on 70.
"There's some tough pins out there," Woods said. "You miss them on the wrong spots, you're going to pay the price, and I think that's kind of what's signified in the scoring. No one is running away with it. Nobody went low today."
Defending champion Graeme McDowell of Northern Ireland, going for a third title in an event he also won in 2010, settled for an even-par 72 that included four birdies and four bogeys.
