THOUSAND OAKS, Calif. (AP) -- Zach Johnson is like most players at the World Challenge, not sure whether he's still playing in 2013 or if he's in the middle of the new wraparound season that officially started in October.
All he knows is that he's leading.
Johnson, who already has two official PGA Tour events under his belt in the ''new season,'' came out a few days early to the unofficial World Challenge to work on new equipment with Titleist at its test center in Carlsbad, and to meet with his team of coaches to outline goals for 2014 and to identify weakness. One priority is to score better on the par 5s, and Johnson wasted little time on that.
Sherwood has five par 5s. He made birdie on four of them for a 5-under 67, giving him a one-shot lead over Matt Kuchar. Hunter Mahan and Bubba Watson were at 70, while tournament host Tiger Woods missed short putts at the beginning and end of his round and had to settle for a 71.
''A highlight that we're looking into next year is trying to play those holes a little bit better,'' Johnson said of the par 5s. ''I don't know what I did that today. I hit it close. I had good shots in there with the proper spin, nothing more than that. But you've got to take advantage of them. You've got five of them. The thing is ... one errant shot, you're staring a 6 right in the face, if not more. There's a lot of penal areas.''
Johnson said he still considers Kapalua to be the start of the season.
Woods, meanwhile, is still trying to get his head around the schedule change. He hasn't played an official tournament in the 2013-14 season. The only event he played was the Turkish Open, where he tied for third in the European Tour event. After this week, he won't play again until Torrey Pines at the end of January. That's his usual starting point, except that the PGA Tour already has had six guys win tournaments.
''To me, I'm still on the old calendar, so to me this is the end of the year,'' Woods said. ''I know that I'm going to be pretty far behind on points by the time I tee up again, and that's just kind of the way it's going to be. ... But you have the entire summer, you have the entire major championship season, you have the big events and then the playoffs. Anything can happen. But it's going to be interesting to see how far behind some of us are when we start.''
This sure didn't feel like summer.
The temperature was in the upper 20s before the sun came up in the foothills of the Santa Monica mountains. There was a one-hour frost delay. A combination of firm turf, chilly weather, some breeze and firm greens made for tough scoring, and it showed.
Steve Stricker was among those under par until a bogey-bogey-double bogey finish put him at 75. Jordan Spieth, coming off a sensational rookie season and playing for the first time since the HSBC Champions in Shanghai a month ago, had a 77 and was last in the field. Jason Day, who won the individual and team title at the World Cup two weeks ago at Royal Melbourne, had a 76.
Rory McIlroy, with girlfriend Caroline Wozniacki following him, was hopeful of building momentum from his first win of the year last week in the Australian Open. He missed a few short putts, found the water on the par-3 15th and had a 73. He played with defending champion Graeme McDowell, who had a 72.
McDowell saw a note that his last eight rounds at Sherwood were in the 60s. That streak ended Thursday, though for good reason.
''The course hasn't been this tough in a couple years,'' McDowell said. ''The scoring reflects that. The greens are much firmer. The speed of them caught me by surprise a little bit today. My speed was a little clumsy, and it showed today on the greens.''
This is the final year the tournament is being played at Sherwood. It moves to Isleworth just outside Orlando, Fla., next year.
Any rust Woods felt had to do with the greens, which he said showed on some of his putts.
''I made a few mistakes today,'' Woods said. ''I also hit a couple of good shots that ended up in some interesting spots. That can happen out there. I shot about the score ... maybe could have gotten one or two more out of it.''
Johnson had few complaints. He opened with two birdies, and then surged ahead on the back nine with five birdies in a seven-hole stretch, three of them on the par 5s. Johnson has a pair of runner-up finishes at this event, and with the tournament moving, this is his last shot at Sherwood.
''I did everything decent,'' he said. ''Just a real solid day all around. I was aggressive when I needed to be aggressive, and I was conservative when I needed to be conservative. It's nothing more than a decent start.''