Orlando - World number one Rory McIlroy finally made a solid PGA Tour start in Thursday's first round of the Arnold Palmer Invitational, but it was Mogan Hoffmann who seized the 18-hole lead at Bay Hill.
McIlroy closed his round with a 14-foot birdie putt to fire a two-under par 70 after struggling in his two prior US appearances this season, a signal his game is rounding into form as the Masters looms only three weeks away.
"There's a lot of the game that's right there, so pleased with that. A lot of positives," McIlroy said. "It could be a really good week."
The 25-year-old from Northern Ireland would complete a career grand slam by capturing the green jacket next month at Augusta National and claim his third consecutive major title after wins in last year's British Open at PGA Championship.
But after a runner-up showing at Abu Dhabi and a win at Dubai to open the year, McIlroy missed the cut at the Honda Classic last month and opened with a 73 for the second event in a row at the WGC event at Doral before fighting back to finish ninth.
Making his first appearance at the event, McIlroy matched a career high by reaching 17 of 18 greens in regulation and had near misses on some long birdie bids.
"If I keep hitting good shots like I did today, hopefully the putts will fall," McIlroy said. "I just need to stay patient."
McIlroy birdied the par-5 sixth after needing only two shots to come within 18 feet of the cup, added a birdie from 17 feet at the eighth, found the water with his second shot at the par-5 16th on the way to a bogey and then closed with flourish to match his low US round of the year.
McIlroy shared 32nd place but was only four shots off Hoffmann's bogey-free 66, which gave the American a one-stroke lead over England's Ian Poulter and Americans Jason Kokrak, Ken Duke, Kevin Na and John Peterson.
World number three Henrik Stenson of Sweden and fouth-ranked Adam Scott of Australia, the 2013 Masters winner, were in a pack of 11 players sharing seventh on 68, as were Scotsman Martin Laird and Irishman Padraig Harrington, coming off a Honda Classic triumph earlier this month.
Hoffmann's round began on the back nine and featured a 33-foot birdie putt at 10 with a six-foot birdie putt at the par-5 12th as well.
But his big shot was a 47-foot chip-in from a greenside bunker for an eagle at the par-5 sixth, an effort sandwiched between tap-in birdies at the par-5 fourth and par-4 ninth holes.
"The key was to finish pretty strong," Hoffmann said. "Holing out on six was a nice little bump there. Today was great."
Hoffmann, 25, has struggled much of this season with three missed cuts, a withdrawal and three finishes outside the top 50. But he shared 17th two weeks ago at Doral and could improve upon his best career US PGA finish, third at last year's BMW Championship.
"I've been missing it both ways and it has been pretty frustrating," Hoffmann said. "Pretty crazy. Golf is a very interesting game."
Reigning Masters champion Bubba Watson withdrew from the event Wednesday. The world number two is mourning the death of a long-time friend.
Leading scores after Thursday's first round of the PGA Tour's Arnold Palmer Invitational (par 72, USA unless noted):
66 - Morgan Hoffmann
67 - Jason Kokrak, Kevin Na, Ken Duke, John Peterson, Ian Poulter (ENG)
- Adam Scott (AUS), Brandt Snedeker, Billy Horschel, Henrik Stenson
(SWE), Harris English, Keegan Bradley, Padraig Harrington (IRL), Martin
Laird (SCO), Hunter Mahan, Matt Every, Ben Martin
69 - George
McNeill, Colt Knost, David Hearn (CAN), Kevin Kisner, Davis Love,
Russell Henley, Webb Simpson, Camilo Villegas (COL), Chris Stroud, Jason
Day (AUS), Louis Oosthuizen (RSA), Sean O'Hair, Justin Thomas, David