McIlroy toils again but Tiger tames Doral

(CNN) -- Rory McIlroy's well documented struggles continued at the WGC Championship at Doral -- but he did complete his round this time.

After McIlroy's walkout at last week's Honda Classic, followed by an apology and a vow never to do it again, the 23-year-old hung in there during a difficult opening day at Doral which he ended on one-over-par.

Despite the world No. 1's woes there was better news for his Nike stablemate Tiger Woods, who carded nine birdies in his round of 66 to take a share of lead in Florida.

That leaves the Northern Irishman down near the foot of the leaderboard and trailing way behind his playing partners -- Woods and Luke Donald -- the world No. 2 and 3 respectively.

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Masters champions Bubba Watson and 2011 U.S. Open champion Graeme McDowell are tied with Woods on six-under, alongside Sergio Garcia and Freddie Jacobson.

McIlroy admitted to Sky Sports after his round he was still far from his best: "It was a bit of a struggle to be honest. I hit some good shots, some not so good shots. I've been saying all week its a work in progress and I'm staying patient.

"I've got another three rounds to work more and try and shoot some scores. I had to play each hole as it came, it was nice to sneak in a few birdies in the last few holes to make it look a bit more respectable.

"I felt like I had more of a clear head; I didn't put too much pressure on myself and that's why I didn't get frustrated."

As for his relationship with the press McIlroy said: "I don't want there to be any friction or tension. Every time I'm asked a question I try to answer open and honestly."

Read: McIlroy sorry for Florida walkoff 'mistake'

Woods looked in fine shape as he made the most of benign conditions at the Blue Monster course, due to be redesigned by American tycoon Donald Trump at the conclusion of this tournament.

He made nine birdies and three bogeys to hit the front and fire an ominous warning to the rest of the field.

"Today is as easy as it gets round here," he said, in comments broadcast by Sky Sports. "The wind is up but not like it normally is. We got to play some of the harder holes down wind which makes a difference."

Phil Mickelson is in a group of players one shot back on five-under after a round of 67. He's joined by fellow Americans Hunter Mahan and Steve Stricker.