Darren Clarke had to produce some short game magic to open with a level par 71 in the $5.8m Valspar Championship but Pádraig Harrington's was missing again as he slumped to a four over 75 to leave himself in danger of missing his fifth cut from his last six starts.

Clarke, who has shed more than 40lbs and reduced his belt size by seven inches since undertaking a strict diet and fitness regime over the winter, soared to the top of the leaderboard over the feared Copperhead Course at Innisbrook near Tampa when he played his first 10 holes in three under par.

But a double bogey six at the 12th and a bogey at the 18th forced the 45-year old former Open champion to settle for a level par round that left him tied for 26th, just three shots behind Americans Matt Every and Pat Perez and Australians Greg Chalmers and Danny Lee.

It was still an encouraging performance from Clarke, now 295th in the world rankings, who was forced to withdraw after an opening 78 in the Northern Trust Open in LA with a recurrence of a chest muscle injury and then shot rounds of 77 and 78 to miss the cut by a distance in the Honda Classic two weeks ago.

He holed a 12 footer for birdie at the par-five first, bogeyed the second after missing the green, but then got up and down from sand for par at the third before holing a cut up wedge shot for an unlikely birdie at the sixth.

(Above) Darren Clarke salutes the crowd after pitching in for birdie at the sixth

He then birdied the seventh with a wedge to just 21 inches, saved par from seven feet at the eighth and repeated the trick from 13 feet at the ninth to turn in two under before rolling in a 19 footer for another birdie at the par-four 10th to grab a share of the lead on three under.

It didn't last, however, and he double bogeyed the 12th, hooking his drive and his approach before fluffing a tough pitch and then missing a five footer for bogey. 

Had it not been for a hot putter, he might have ended up close to Harrington on the leaderboard.

He had to hole a six-footer for par at the 14th, a nine-footer at the 15th, a five footer at the 16th before missing a seven footer for par at the last.

Harrington, on the other hand, was never comfortable and made just one birdie — a holed bunker shot at his 17th hole — and has now broken par in just four of the 11 rounds he's played on the PGA Tour so far this year.

Ranked 147th in the word, a slide of nearly 100 places over the past 12 months, the 42-year old Dubliner missed a six footer for his par three at the 13th and dropped another shot when he missed the tough 16th green.

But after avoiding a bogey at the 17th thanks to a seven foot putt, he missed a four footer for birdie at the par-five first and an eight footer for par at the third to go three over for the day.

(Above) Harrington manages a smile as he holes his bunker shot at the eighth

Struggling to hit the ball close, he had to hole a six footer just to avoid a three-putt bogey at the fourth but there was to be no respite.

At the seventh he three-putted from 47 feet, missing from inside six feet for par. And while he holed a long range bunker shot for a two at the eighth, he missed his seventh green of the day at the ninth and again missed from 10 feet for par.

With a scrambling success rate of just 43 percent he ended the day tied for 116th place as he desperately seeks a win that would help him to avoid missing the Masters Tournament for the first time since he made his debut at Augusta National in 2000.

Every, Chalmers, Perez and Lee lead by a stroke from a group of six players including Europeans Nicolas Colsaerts and Matteo Manassero.