A nervous Stuart Appleby, making his PGA Tour Champions debut, shares the lead after the first round of the Pure Insurance Championship in California.

The Australian, who turned 50 on May 1, is tied with Germany's Alex Cejka, after both shot six-under-par 66 at Pebble Beach Golf Links.

Tom Lehman, who played Pebble Beach, and South Korea's KJ Choi, who played Spyglass Hill Golf Course, both shot five-under 67 to share third place.

Glen Day, Kirk Triplett and Mexico's Esteban Toledo, who all played Pebble Beach, and Larry Mize, who played Spyglass Hill, are tied for fifth place at four under.

Appleby, a nine-time winner on the PGA Tour, carded seven birdies and just one bogey.

"I had no idea what to expect," he said. "I was a bit nervous starting. I haven't played any golf really at all, much. Just getting 18 holes completed has been really difficult.

"So and then walking the practice rounds, didn't really know how I'd feel. Legs pretty tired. Game was pretty rusty today. Sort of felt - felt all right.

"I got off to a good start. I was a bit nervous, with the cameras around. I haven't really seen anything like that for a while. So that was a bit strange ... so I was happy to get out of the day."

Cejka completed a bogey-free round. He is looking for his third Champions victory, having won the Regions Tradition and the Senior PGA Championship, both in May

He was the first PGA Tour Champions player to win his first two majors since Arnold Palmer (1980-81).

But in nine tournaments since his second win, Cejka never finished higher than a tie for fifth while recording just two top-10 results.