The 41-year-old American ran up a triple-bogey seven at the 10th that left him on four over, although birdies at the 15th and 18th boosted his chances of making the cut, which he has missed only once in 20 visits to the course.

"I never knew they had jungle like that over there. Nuts, that was so far left," said the left-hander, who won the tournament in 2004, 2006 and 2010.

"The key was getting through 11 and 12 and some pars, taking advantage of the par fives.

"I got two of them back coming in, so as poorly as I played and some of the poor shots I hit and the mishaps, missing on the wrong spot, I'm right there.

"And with a hot round tomorrow, I'll get right back in it for the weekend. I know that heading in I've been playing well so I'm going to fire at it tomorrow and see if I can do that."

Charl Schwartzel made a steady start to the defence of his Masters title with a level-par 72.

The South African started his final round last year by chipping in for a birdie at the first then making birdies on each of the last four holes to clinch his first major title by two shots.

However, the 27-year-old was battling just to hold par as he returned to the scene of his triumph.

He salvaged a par on the first hole and played the last four in one over, carding bogeys on the 15th and 18th holes and a birdie at 17.

"I felt good out there. I hit some really good shots," said Schwartzel. "My golf swing felt like I was in control of it and it could have easily been a two or three-under-par day.

"But it was a disappointing finish with a bogey out of the middle of the fairway. I wish I played like Sunday last year."