Luke Donald faced an anxious wait as officials investigated a potential error on his scorecard that could have seen him disqualified from the Masters.
Donald was put down for a one-over-par 73, but had in fact gone round in 75.
The penalty for signing for the wrong score is disqualification.
But officials discovered a smudge on the Englishman's scorecard was the cause of the confusion and the 34-year-old world number one was cleared to continue his bid for a first major.
The misreading caused the official leaderboard to display Donald as shooting a birdie at the par-four fifth hole for more than an hour. He had actually completed it in five.
In interviews after completing his round and before the issue emerged, the world number one had spoken of being three over at the par-72 course, indicating the error was not his mistake.
"I three putted five and six and three over at that point and playing catch up. I didn't hit enough greens and give myself enough opportunity for birdies," he said.
"Just talked to Luke. Scorecard was correct," Donald's coach Patrick Goss tweeted. "Luke doesn't make that mistake. Too diligent and detailed."
Donald's wife Diane tweeted: "Just got off the phone with Luke, NOT disqualified. Thank goodness."
However, the world number one will have a lot of ground to make up in his second round after finishing eight shots behind first-round leader Lee Westwood, who shot a five-under-par 67.
"If I can go out tomorrow and get back in the red numbers hopefully I will be in the mix," said Donald.
"I'm going to the range to work on my irons. I was a little bit off with those. I struggled with a bit with mud on the ball but everyone did."