Mike Weir turned in a bogey-free  second round on Friday to grab a one-shot lead at the PGA Tour's season-opening Mercedes-Benz Championship.

The Canadian carded a six-under-par 67 and is at eight-under 138 after 36 holes.

Weir carded five birdies and three bogeys for an opening 71 on Thursday, and he followed up with four birdies and an eagle on the Plantation Course at Kapalua, which is the lone par-73 layout on the PGA Tour.

Canadian Stephen Ames and Jonathan Byrd are tied for second at seven-under.  Ames fired seven birdies and a bogey for a 67, while Byrd carded a 69 that included five birdies and a bogey.

The winner of the 2003 Masters, Weir played the front nine in four-under, including an eagle at the par-five ninth.  He had a pair of birdies on the back nine — at numbers 15 and 18 — to grab the lead.

The field averaged 73.65 on Thursday, but Weir was among many players who found the course there for the taking in the second round.

"It was easier out there with the wind not as strong," Weir said.  "I'm pretty happy.  Things are going good so far for it being the first tournament of the season."

Ames has things going pretty good as well, especially considering he got into this winners-only event with a victory at the last event on the 2007 PGA Tour schedule, the Children's Miracle Network Classic.

He birdied number two and four before a bogey at the seventh.  Ames bounced back from his lone miscue of the round with consecutive birdies to close out the front nine.

A set of birdies at 14 and 15 and another at 18 put Ames right in contention as he hopes to start the new season just as he ended the last one.

Brandt Snedeker (69) and Nick Watney (72), who led entering the second round, are tied for fourth at six-under 140.

Defending champion Vijay Singh signed for a 70 and is tied for 17th at two-under.