Australian Adam Scott set the clubhouse target with a six under par 66 at the WGC-Cadillac Championship as Luke Donald won the battle between the world’s top three golfers.
Scott’s round set the pace for a 74-strong field that included all the Official World Golf Ranking's top 50, but Americans Steve Stricker and Jason Dufner were only one behind with three and four holes to go respectively.
Rory McIlroy managed only a one over par 73 in his first round as World Number One - and as a result was seven shots off the early pace at the second of this year's World Golf Championships.
The 22 year old Northern Irishman mixed three birdies - all at par fives - with four bogeys in windy Miami.
He still beat Lee Westwood by three, but Donald - who could take the top spot back off US Open Champion McIlroy this week - shot 70 and took the honours after golf's three highest-ranked players were paired together.
Leading Europeans at that point on four under was Dane Thomas Björn, while Tiger Woods, second to McIlroy at the Honda Classic after a personal-best closing round of 62 on Sunday, was one under after 13 - something of a disappointment after he started as he finished in Palm Beach Gardens with an eagle.
The up and down pattern of McIlroy's day was established early. He missed the green at the 11th, his second, and bogeyed, but came back with an 11 foot birdie putt on the next.
He almost found the water off the tee at the demanding 18th, dropped another shot, but then almost matched Woods' eagle on the long first.
Then came two bogeys in a row, however, and it could have been worse. His approach to the third hit the rocks by the water, but bounced left and returned to grass.
A pitch to four feet at the par five eighth brought McIlroy his last birdie, but he has already left himself a lot of ground to make up.
Not as much as Westwood, though, and his score probably rules him out of the victory which could restore him to the World Number One spot he relinquished to Donald last May.
The 38 year old, whose closing 63 last week was his best-ever round in America, bogeyed the first three holes, turned in 40 and remained four over coming home.
Paul Casey, playing for the first time since dislocating his shoulder snowboarding on Christmas Eve, also returned a 76 - and so did Ian Poulter a week after being diagnosed with pneumonia.
Justin Rose, in contention last week before slipping to fifth, had four birdies in six holes from the eighth and that lifted him to three under.
Scott won last August's WGC event in Akron and said: "You know it's only a month until The Masters and this is the time you want to knuckle down and get involved."
Björn did not have a bogey and stated: "When it's this windy you know you need to play solid golf and keep the big numbers off your card. That's what I did."
McIlroy said: "I was mentally flat and it was a bit of a struggle.
"It was a pretty tricky day, but obviously there was good scores out there. I just didn't really get anything going.
"After what happened last Sunday - Tiger shoots 62, I end up winning to go to World Number One - obviously people are going to talk, but I think everyone has to remember that there's 80 other players in this field or whatever it is (it's 74) and it's not just about a couple of guys.
"All of a sudden you're there (top of the rankings) and you're like 'Well, what do you do?'. I just need to go out and set myself a target tomorrow.
"There's going to be times where you're going to feel a little bit off and it's just trying to handle those the best you can."
Donald said: "I played pretty solid. I've struggled a bit getting off to a quick start, but I was pleased with my putting - that's always the key for me. If I roll it well the rest of it becomes a bit easier."