American Patrick Reed held a one-shot lead after the completion of the first round of the weather-delayed WGC-Cadillac Championship on Friday.
The 23-year-old Texan posted a 68 over the revamped Blue Monster layout at Doral to sit at the top of the leaderboard on four-under, one clear of a group of six players.
That posse included five Americans; Harris English, Jason Dufner, Dustin Johnson, Matt Kuchar and Hunter Mahan, as well as the leading European contender, Francesco Molinari of Italy.
Rory McIlroy heads up another group of six on two-under as he bids to improve on last week's near miss at the Honda Classic when he surrendered a three-stroke final round lead.
However, Tiger Woods' recent woes continued as he endured another difficult morning, eventually signing for 76 - his worst-ever round at a tournament he has won on seven occasions.
Having finished on two-over through ten holes before play was abandoned on Thursday, Woods endured a nightmare start on his return and promptly dropped four shots in his first four holes - including a double-bogey six at the 14th.
He did repair most of that damage with a run of three straight birdies, but a bogey at the tough par-four 18th ensured he ended on four-over and in a tie for 53rd.
Woods & Scott struggle
Woods' playing partner Adam Scott also struggled to make any impact as he signed for a three-over 75.
The Australian could usurp the American as world No 1 with a victory this week - combined with Woods finishing outside the top ten - but that now seems highly unlikely.
McIlroy fared much better as he returned to polish off the four holes he had left from Thursday, picking up two birdies in three holes before giving one back at the ninth to post a solid 70.
Just two off the pace, the Northern Irishman found himself alongside Luke Donald, Miguel Angel Jimenez, Charl Schwartzel, Zach Johnson and Ryan Moore.
But they were all left looking up at Reed who would complete a opening round that contained seven birdies and three bogeys.
The two-time PGA Tour winner - who won at the Humana Challenge in January - took over at the top after claiming the final birdie of his round at his penultimate hole, the par-five eighth.
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