THOUSAND OAKS, United States- Zach Johnson got hot on a chilly Southern California day Thursday to seize a one stroke lead in the World Challenge, with tournament host Tiger Woods four adrift.
Johnson had seven birdies in his five-under par 67, and said his only really poor drive of the day cost him his second bogey at the par-four 18th.
"I did everything decent," he said. "I wedged it really good. Any time I had a wedge in my hand, I seemed to be hitting my lines and my yardages. I putted it great. Just a real solid day all around."
Johnson was one shot in front of Matt Kuchar, whose four-under 68 was highlighted by an eagle at the par-five 11th.
Hunter Mahan and Bubba Watson shared third on 70, followed by Woods on one-under 71 - the only players in the elite 18-man field for the unofficial event under par.
"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.
McDowell played alongside compatriot Rory McIlroy, who notched his first victory of 2013 with a stirring triumph over home favourite Adam Scott at the Australian Open last Sunday but didn't see any momentum carry through in the first round at Sherwood Country Club.
McIlroy had three birdies but four bogeys in his one-over par 73.