KAPALUA, Maui — By tomorrow maybe we will know if there is a connection between the bad weather that has beat Hawai'i up recently and the fact that a couple of Canadians and two sick guys are on top of the Mercedes-Benz Championship leaderboard halfway through the PGA Tour's first tournament.

Mike Weir, the most successful Canadian in tour history, seized the lead yesterday with an 18-foot birdie putt on the final hole at Kapalua's Plantation Course. The second round was transformed into a birdie free-for-all when the wind let up a little and the rain held off until the final hour. Ultimately, the difference for Weir was the first eagle of the 2008 season, which he bagged on the ninth hole.

Only nine golfers broke par in Thursday's aggravating opening round of 2008, punctuated by difficult wind and relentless rain. Yesterday, all but seven in the 31-golfer field were under par. The Plantation played to an average of 70.645, the first sub-71 average since the third round in 2005.

Mark Calcavecchia, 47, fired the day's low round of 7-under-par 66, with nine birdies. He needed 35 putts — wielding standard size and belly putters — during an opening-round 75. Yesterday he put away the short one, which earned him an invitation here as the 2007 PODS Championship winner, and needed just 29 putts — with three 3-putts; the first came on the fourth hole, where his 50-footer ran wild and became a 47-foot second putt.

"The main difference today was, No. 1, it was a lot easier to play, not a downpour every five minutes," said Calcavecchia, who took advantage by hitting every green in regulation. "And it wasn't quite as windy."

And "I made putts today. I putted great."

He was hardly alone.

Weir, Dean Wilson's teammate at Brigham Young, and Stephen Ames both shot 67. Jonathan Byrd birdied three of the last four for a 69 that tied Ames for second at 7-under 139. First-round leader Nick Watney never really got it going and still shot 72 to share fourth with Brandt Snedeker (69), who would be running away with this but for the pesky final holes.

Thursday, the 2007 Rookie of the Year had his driver crack on the 17th tee and he finished double-bogey, bogey. Yesterday, he was 8-under after 10 holes, bogeyed two of the next three but had a 17-foot birdie putt to join Weir at 8-under on the final hole. He missed that and the 2 1/2-footer coming back.

Snedeker and Byrd are still recovering from holiday illnesses, which hardly explains their rise to the top the last two days.

Ames has been here since Dec. 20 and keeps insisting golf is "getting in the way of my vacation." He played just 18 holes to warm up for Mercedes — two nine-hole skins games with his young sons. With $5.5 million at stake tomorrow, and the bulk of the crowd seemingly from Canada and following he and Weir, he might start to take it seriously.

Watney and Daniel Chopra teed off in the final group yesterday with 36 people in the bleachers. That number was dwarfed by the Canadians getting up close and personal with Weir and Ames, who was born in Trinidad and gained Canadian citizenship in 1998. "I guess the winters are pretty bad in Canada," Weir shrugged.

Ames' grandmother, a two-time Trinidad and Tobago champion, started him in the game. Ames' wife is from Calgary, which is where they live now. He characterizes his move as a "great step for me and my career, and obviously our family."

Ames, 43, spent last year working on his swing, winning his third tour event and finishing in the top 12 at the U.S. Open and PGA Championship. He spent his limited practice time leading up to yesterday's round working on his putting, which paid off with a 26-putt round.

Weir, the 2003 Masters champion, had 28. He one-putted the final four greens on the front and the back, playing those holes in 5-under and preventing a bogey from finding his scorecard.

Weir has eight tour titles, which ties him with George Knudson as the winningest Canadian. Last year's victory in the Fry's Electronics Open was his first in four years. The season was also highlighted by a 1-up win over Tiger Woods in the Presidents Cup in Montreal.

"The things I've done so far in my career, and then to have that was pretty special," Weir said. "I feel, relieved is the word, that the whole thing is behind me and I feel relaxed."

Zach Johnson, last year's Masters champ, opened with a 76 but rallied into a share of 13th with a 67. Angel Cabrera, the reigning U.S. Open champion, shot 71 to grab a share of sixth.

NOTES

Nearly a third of this week's field will not play in next week's 10th anniversary of the Sony Open in Hawai'i, the first full-field event of year.

The number not moving on to O'ahu is extraordinarily high, and includes Mike Weir, Nick Watney, Justin Leonard, Scott Verplank and Hunter Mahan.

Sony will have 14 players from the top 50 of the World Golf Ranking and half of last year's top-30 money winners, including former champions Jim Furyk and Vijay Singh, Steve Stricker, K.J. Choi, Rory Sabbatini, Angel Cabrera, Zach Johnson, Aaron Baddeley and Stephen Ames.

Champions Tour members Fred Funk and Jeff Sluman, the inaugural Sony champion, are also in the field.

Sony will be the first tournament to use the new cut, approved by the PGA Tour Policy Board. The low 70 pros and ties, as usual, will play on the weekend unless that brings in more than 78 players. In that case, the cut will be made at the number closest to 70.

Reach Ann Miller at amiller@honoluluadvertiser.com.