World number one Rory McIlroy ended the first day of the WGC-Cadillac Championship 11 shots off the lead after a rollercoaster opening round at Doral.
McIlroy carded three birdies and an eagle in the space of five holes on his back nine, but also recorded four bogeys and a double bogey to return a one-over-par 73.
In contrast, American JB Holmes returned a flawless 62 featuring eight birdies and an eagle to lead by four shots from compatriot Ryan Moore, who was eight under par until a double bogey on the 18th.
"It was a great day for me," Holmes told Sky Sports 4. "I hit it real good again today and made some putts. I made a couple of long ones and hit a couple of real good iron shots in there."
Moore revealed he had "found something" in his swing while practising last week, adding: "I controlled the ball better than I have for years and rolled in some nice putts out there today. It was a great round of golf and I'm not going to let the last hole ruin it for me."
McIlroy described missing the cut in last week's Honda Classic as a useful "kick up the backside" ahead of his bid to become just the sixth player to complete the career grand slam by winning the Masters at Augusta next month.
But it did not appear to have had the desired effect as the Open champion struggled to four over par after nine holes of his opening round on the "Blue Monster" to lie joint 69th in an elite field reduced to 73 players by the withdrawal of Thomas Bjorn.
Starting on the back nine, McIlroy failed to birdie the par-five 10th and then bogeyed the 11th after finding a greenside bunker with his approach and missing from 12 feet for par.
The 25-year-old also failed to get up and down from sand on the 17th before a costly double bogey on the 18th, where he found the middle of the fairway with a superb drive but then pulled his second shot into the water left of the green.
McIlroy finally recorded his first birdie of the day on the par-three fourth, holing from 10 feet to get back to three over par, and made it two in a row from close range on the next.
A wayward approach to the sixth finished on the edge of a greenside bunker and led to another bogey, before McIlroy holed from 18 feet for birdie on the seventh and 22 feet for eagle on the par-five eighth after a superb long-iron approach.
Getting back to level par was an impressive achievement in the windy conditions but McIlroy pulled his tee shot to the ninth left of the green and chipped his second into a bunker, eventually doing well to hole from 12 feet for a closing bogey.
The top 50 players in the world are all competing at Doral with the top 24 grouped in ranking order, meaning McIlroy played alongside Bubba Watson and Henrik Stenson, who shot 71 and 69 respectively.
"I'm very happy," Stenson told Sky Sports 4. "I thought I kept my concentration and patience out there which you really need this week and where we are going in about four weeks' time (Augusta). My game felt pretty good as well.
"It's tough conditions out there, the wind is blowing and this is a very difficult course after the remake. The line between disaster and brilliance is so slim so I am happy with the way I performed out there."
France's Alexander Levy shared third place with Dustin Johnson and Rickie Fowler after an impressive 68 on his tournament debut, with last year's runner-up Jamie Donaldson shooting 70 and Ireland's Shane Lowry 71.
Scotland's Stephen Gallacher propped up the field on 12 over par after twice finding water on the 18th to run up a quadruple bogey eight in a back nine of 46.