Rory McIlroy and Justin Rose both made nightmare starts to the British Open at mighty Muirfield on Thursday as US wedge-king Zach Johnson set the early pace with a 66.

World No.2 McIlroy, desparately seeking the form that has eluded him since he changed clubs at the start of the year, had two double bogeys down the back nine en route to a morale-sapping eight over 79.

The lowest point of his round came at the 15th where he shook his head in disbelief after watching his long putt speed over the rock-hard green and bury itself in a deep pot bunker.

A second double-bogey was the end result of that and he looked a disconsolate figure trudging off the 18th green with the question mark over his current form beginning to take on giant proportions.

“I sort of hung in there. I made sloppy bogeys on four and five, then a good birdie on seven. I let shots get away from me - too many loose shots,” the 24-year-old McIlroy said.

“Silly mental errors cost me. I missed the ball in wrong places - you can't do that with the firmness of the greens.

“I made stupid mental errors. It's got so fast and firm. If you're not in total control of the golf ball it'll be quite difficult.”

Lone birdie

Last month's US Open winner Rose needed 17 holes before bagging his only birdie of the day and a double-bogey and three bogeys meant that he came in with a disappointing 75. Both McIlroy and Rose failed to deal with the exceptional conditions at Muirfield, where two weeks of pure Scottish sunshine had left the famed links course running fast and furious.

More blue skies and temperatures nudging 26 degrees Celsius on Thursday made the greens treacherous and at times Augusta National fast, especially around the pins.

Johnson, whose sole win in a major came at the 2007 Masters, where his exceptional wedge play was the key, eagled the par-five fifth to set him on his way to a tremendous five-under 66.

Johnson waved his putter like a magic wand to birdie the third, sixth and seventh and eagle the long fifth. The 37-year-old made further inroads on par at the par-four 12th before dropping his only stroke of the day at the 14th.

A shot further back came rising Spanish star Rafael Cabrera-Bello, with three players grouped on 68 — Spanish veteran Miguel Angel Jimenez and American sharp-shooters Dustin Johnson and Brandt Snedeker.

Todd Hamilton, who upset the odds to win the 2004 Open at Troon, was on 69 and he was joined there by Angel Cabrera of Argentina, and four-time major winner Phil Mickelson, who won last week's Scottish Open

“I love the fact that I shot under par, because it's a very challenging course out there. I don't expect anybody to beat the lead from the morning wave,” said Mickelson.

Nick Faldo's return to Muirfield, where he won the Open twice, failed to find a spark as he struggled to a 78, while “golden oldie” playing partners, Tom Watson and Freddie Couples also found it tough going with a pair of 75s. “The golf course is tough, you know. It's hard work,” said the semi-retired Faldo. — Agencies

Kapur tied fourth

India’s Shiv Kapur was three-under after 15 holes to lie joint fourth in the opening round on Thursday.

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