This event is reserved for winners from last year's official PGA TOUR schedule with 34 players teeing it up at the Plantation Course at Kapalua Resort. Only two players who hoisted trophies last year did not play this week - major winners Tiger Woods and Phil Mickelson.
Thursday's opening round also marked the first round of the inaugural season-long FedExCup, which culminates with a $10 million first-place prize later this season at the TOUR Championship.
'It's hard when you hit a 9-iron from 200 yards and turn around and hit 9-iron from 100 yards,' said Davis Love III, who is alone in sixth place at 3-under-par 70.
Singh, whose only win last year came at the Barclays Classic, flew out of the gate on Thursday with a pair of birdies at one and two. He narrowly missed an eagle chance at the fifth, but tapped in for birdie to reach 3-under par.
The former world No. 1 dropped a shot at the seventh and made pars around the turn. Singh hit a 408-yard drive at 12 and reached the green, but two-putted for a birdie.
Singh bogeyed 13, but took advantage of his length again at the 14th and kicked in a short birdie putt. He joined the group at 4-under par with a 4-foot birdie putt at the 15th.
Singh found a few bunkers on the way into the clubhouse and never gave himself a great look at birdie. He settled for a share of the first-round lead.
'I know the golf course pretty well, but this wind was something else,' said Singh. 'I just went out there with a very positive vibe and said I've got to hit solid shots, and that was my objective today.'
Choi, who got into the field thanks to a win last year at the Chrysler Championship, got off on the wrong foot with a bogey at the third when his approach sailed over the green.
That would be Choi's last mistake of the front nine as he went on a birdie run. He two-putted for birdie at the par-5, then rolled in a 10-footer for birdie at seven. Choi knocked his tee ball to tap-in range for birdie at eight and polished off three in a row with a 2-footer at nine.
Choi appeared headed to a fourth birdie in a row at the 10th, but his birdie putt from 10 feet flew 4 feet past thanks to the wind. He missed the comeback putt, but atoned for the error with a 3-foot birdie putt at the driveable, par-4 12th.
Choi closed his round at 18 with a birdie when he missed the green with his second at the par-5 hole, but chipped to 3 feet with his third.
'As far as my swing, everything was feeling good, stroke was good, windy conditions were definitely prevailing,' said Choi. 'However, it's a very important day for the FedExCup in 2007 and I'm glad I finished the first round real well.'
MacKenzie, last year's winner in Reno, tallied two birdies in his first five holes, but bogeyed No. 8. At the par-five ninth, MacKenzie hit his third shot right of the hole, then watched the ball spin into the cup for an eagle.
He three-putted from 42 feet for a bogey at the 13th, but back-to-back birdies from the 15th got him into a share for the lead.
'I hit the ball really well out there for the most part, and I putted well, as well, so it was a good combination,' said MacKenzie.
Ames, in one of Thursday's later groups, played the first 13 holes in one- under par, thanks to a pair of birdies a one bogey. He birdied No. 14 to get to minus-two, then it was his strong finish that moved him up the leaderboard.
At the difficult, par-4 17th, Ames drained a 20-foot birdie putt to get within one of the lead. One hole later, his 24-foot birdie try found the bottom of the cup and suddenly the Players Champion found himself tied atop the leaderboard.
'Today was a tough day,' acknowledged Ames, who also won The Skins Game in the offseason. 'Coming out here, after time off, I'm quite pleased.'
Wetterich notched an eagle, two birdies and three bogeys to reach the 11th tee one-under par. He birdied 14 and 15, then nearly holed a 40-foot eagle try at the last before settling for birdie.
'I can't remember the last time I played in wind like this,' admitted Wetterich. 'It was really tough. I'm going to keep playing hard and see what happens.'
Jim Furyk, the 2001 winner, Chris Couch, Rory Sabbatini and 2006 PGA TOUR Rookie of the Year Trevor Immelman are knotted in seventh place at 2-under-par 71.
Three-time defending champion Stuart Appleby is tied for 13th place at even-par 73.