(Reuters) - Adam Scott's first competitive round as golf's top-ranked player featured two contrasting nines as he finished five strokes off the early lead at the Crowne Plaza Invitational in Fort Worth, Texas on Thursday.

The Australian, who dislodged  from the game's pinnacle on Monday, struggled to an outward four-over-par 39 at iconic Colonial Country Club before making three birdies after the turn to card a one-over 71 in the opening round.

That left Scott well behind New Zealander Tim Wilkinson, who reeled off four birdies in a flawless 66 to set the early pace in the prestigious PGA Tour event won five times by golfing great and Fort Worth resident Ben Hogan.

"I thought I actually hit plenty of good shots and played from the fairway for four over, so it wasn't ideal," Scott told reporters about his start after teeing off at the par-four 10th. "But I managed to tighten up on the back and make a couple of putts."

Scott, just the second Australian to become number one following Greg Norman's final reign which ended in 1998, bogeyed the 11th, 15th, 17th and 18th as he limped to the turn.

However he then upped a few gears, reaching the green in two at the par-five first and two-putting for birdie before picking up another shot at the par-four second where his approach ended up three feet from the hole.

"All of a sudden, I had the momentum going the way I wanted and I managed to hang on for the next few holes," Scott smiled. "It's a testing golf course. I just have to be a little patient.

"Sometimes on a course like this, you need to be. Even with a short iron or a wedge in your hand, you can't force it because bogeys are easy to come by."

Scott played the opening round in high-profile company, twice Colonial champion Zach Johnson carding a 70 and his fellow American Jimmy Walker, the FedExCup points leader, returning a 67.

"It was a fun day," said Walker, who has triumphed a season-high three times on the 2013-14 PGA Tour. "There was a good vibe in the whole group. It was very calm and mellow."

Wilkinson, who has bounced between the PGA Tour and the satellite circuits since he began competing regularly in the United States in 2005, recorded three birdies on his front nine to reach the turn in three-under 32.

The 35-year-old from Palmerston North, whose best PGA Tour finish was a tie for second at the 2008 Texas Open, also birdied the par-four 17th on the way to the clubhouse lead.

American Boo Weekley, who won last year's title to get his name engraved on the Wall of Champions by the first tee, was among the late starters on Thursday.

 

(Reporting by  in Los Angeles; Editing by Frank Pingue)