American Lexi Thompson was left in tears after being handed a four-stroke penalty.
Lexi was leading the final round of the first major of the season before the decision to penalize her.
The American ended up losing the play-off to Ryu So-yeon.
The penalty
Lex was caught on camera incorrectly replacing a marked ball in Saturday’s third round.
Aa TV viewer who spotted the offence notified the officials.
She was leading the ANA Inspiration by two shots when told of the penalty after her 12th hole.
She birdied the 18th to force a play-off which Ryu won at the first hole.
Thompson, 22, had missed a 20-foot eagle putt on the last that would have given her a sensational victory at Mission Hills in California.
Caught on camera
Thompson appeared to put a marker at the side of her ball on the 17th green before lifting it and replacing in front of the marker prior to a putt of less than two feet.
The LPGA said she “breached Rule 20-7c (Playing From Wrong Place), and received a two-stroke penalty. She incurred an additional two-stroke penalty under Rule 6-6d for returning an incorrect scorecard in round three.”
Her five-under-par third-round 67 was changed to a 71.
“Is this a joke?” Thompson said after being informed by a rules official, before making birdies on three of the last six holes to force the play-off.