Jason Dufner follows through on his tee shot at the par-five 16th hole Thursday… (David Cannon / Getty Images )
ORLANDO, Fla. — Anthony Kim had the hole-in-one, Charlie Wi had the finishing flourish and Jason Dufner was a picture of steady progress.
Birdies on two of his final three holes lifted Wi's name to the top of the Arnold Palmer Invitational leaderboard, carding a six-under-par 66 that gave him a two-shot advantage over his nearest pursuers as the morning groups finished at Bay Hill Club & Lodge.
Wi had predicted his score might not hold up and he was right, as Dufner came through with the afternoon groups to post an impressive round ending with a duplicate 66. Dufner had just one bogey for the round and an eagle three on the par-five 16th.
"I've never really done well here," said Wi, whose previous body of work at Bay Hill has been last year's tie for 24th, two missed cuts and a withdrawal.
"If I had known (I'd be) a couple under today before I teed off, I would have been very pleased. To shoot 66 is a pleasant surprise."
Nick Watney led the chase pack after an opening 68. Tiger Woods was among seven players another stroke back at three under, walking away with a ho-hum 69 that included solid ballstriking but also a pair of three-putt bogeys.
"Could have shot five-under par without hitting it real close," said Woods, who added that he hardly gave any thought to the sore Achilles that has been the golf world's focus for the past 10 days.
"Not in my mind at all," he said. "I'm just out there playing. I'm feeling good; I've been getting treatment. Everything's good. No swelling."
Justin Rose, winner at Doral two weeks ago, also was among the group at three under, along with Players Championship titleholder K.J. Choi, Sean O'Hair, Jimmy Walker, Bubba Watson and Kim.
Kim aced Bay Hill's 203-yard 17th hole, finding the range with a five-iron. Unsure that it went in, he needed confirmation from playing partner Zach Johnson before breaking a smile.
Hitting the green has been an issue," he said, "so making it in the hole was nice."
Kim, still trying to get rid of bad habits picked up while battling a wrist injury, has made the cut just once in six previous starts this year.
It wasn't the only ace on the day as Ryan Moore carded a late hole-in-one at No.7 from 203 yards away with a 5-iron. Moore, however, was only able to get in at one-under-par 71.
Phil Mickelson opened with a one-over 73, though he battled back from a pair of early double bogeys to birdie three of his final six holes.
Players were greeted by sunny skies and brezze that got stronger at midday, helping a Bay Hill layout that was revamped three years ago hold its own.
"We didn't make any major changes," said Palmer, who once tinkered with the layout annually but has eased off since the upgrade.
"Through the years, we will continue to do the things that we are doing to make the golf course better, and to make the players come here and enjoy the competition."
One place this week's entrants should avoid: Bunkers. The soft sand that confounded players last year is back, with plenty of opportunity for plugged lies.
"You've got to expect it here," said defending champion Martin Laird. "Three out of four balls are probably going to plug, so that's just to be expected. The bunkers are a true penalty around this golf course."