Updated

By Mark Lamport-Stokes

THOUSAND OAKS, California (Reuters) - Former Masters champion Zach Johnson, energized by a two-week break, charged into a share of the lead in the Chevron World Challenge first round on Thursday.

In the absence of troubled tournament host Tiger Woods, the straight-hitting Johnson took advantage of ideal scoring conditions to fire a four-under-par 68 at Sherwood Country Club.

Johnson ended a day of dazzling sunshine and hardly a breath of wind level with Britain's Ian Poulter, who held a two-shot lead over his 17 rivals in the elite field before double-bogeying the last.

Three-times major winner Padraig Harrington of Ireland opened with a 69 to finish a stroke in front of Americans Jim Furyk and Stewart Cink and South Korean Yang Yong-eun.

"I wanted to come here fresh and that I am," Johnson told reporters after recording birdies on all four of the par-five holes at Sherwood.

"I took 16 days off before I hit a ball after (the) Disney (Classic), and most of it was by choice. There were a couple of times I could have practiced but I just didn't do it.

"My point this week is a week to get ready for the 2010 season and for me to work out. It's going well."

The absence from Sherwood of 14-times major champion Woods has been a major talking point for the players and the fans, and Johnson said the atmosphere was noticeably different.

"I think there's less of a buzz, as chaotic as it really might be if he had been here," Johnson said. "I wish he was here, granted, and there's certainly less media here."

World number one Woods pulled out of his own event on Monday, citing injuries from a mysterious car crash outside his Florida home last week as speculation began to escalate over his private life.

On Wednesday, Woods apologized for "transgressions" in a statement that apparently addressed allegations he had extra-marital relationships.

(Editing by Ian Ransom)