Stenson looked set to celebrate his 36th birthday in style when he opened up a three-shot cushion at six under following a birdie at the 10th.

He had stormed to the top of the leaderboard with eagles at the second and eighth holes and another birdie at the fifth.

The former world No 4, who has slipped to 171st in the rankings after a barren spell, sandwiched a third birdie at the 15th with two bogeys at 14 and 16 but still held a two-shot advantage on the 18th tee.

Hooked

However, he hooked a three wood into the trees, failed to find the fairway with his second shot and then topped his third.

Stenson's fourth shot flew through the green and he left his chip short before missing a three-foot putt for a seven and his eight - which equalled the highest-ever score at the 18th - left him with a one-under 71.

He told Sky Sports: "I'm not too happy with that finish. I was struggling the whole back nine, didn't hit a fairway after 11.

"We were in the pine needles and hitting over trees and all sorts for most of the back nine.

"The real problem is that we misjudged the wind on the last and to walk away with an eight on the 18th hole is really disappointing.

"I made two great eagles on the front nine which is a good achievement at Augusta, but I wish I could have got away with something less than a snowman on the last.

"I made some great putts and recoveries but if I can't hit a fairway on the back nine, it's not really where I want to be, is it?"