In a rare occurrence or rather a first of its kind, America’s Lexi Thompson was literally robbed of her second ANA Inspiration title after being handed a four-stroke penalty while leading in the final round of the first major of the season on Sunday. Thompson rallied to card a closing five-under 67 and tie at 14-under 274 with South Korea’s So Yeon Ryu, who had a 68. India’s Aditi Ashok, who made her maiden Major cut, finished tied 42nd as she compiled a 75 in the final round. She carded 72-69-72-75.

Thompson lost to Ryu after a television viewer spotted a missed offence that the 22-year-old American unintentionally had made on Saturday. Thompson was handed the penalty after she incorrectly replaced a marked ball in Saturday’s third round.

Thompson was leading the Championship by two shots when she was informed about the penalty. The incident occurred when Thompson had put a marker at the side of her ball on the 17th green before lifting it and replacing in front of the marker before a putt of less than two feet.

The LPGA said in a statement: “On Sunday afternoon, the LPGA received an email from a television viewer that Lexi Thompson did not properly replace her ball prior to putting out on the 17th hole during Saturday’s third round of the ANA Inspiration. She was immediately notified of the breach by LPGA Rules Committee in between holes 12 and 13 of the final round.”

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. “It is unfortunate with what happened, I did not mean that at all, I had no idea that I did it,” Thompson said. “I had to regroup myself, my caddie helped me out tremendously, we have a great relationship. I tried to gather myself and I made a great putt at 13. But it’s all to the fans, they helped me get through the rest of the round and I thank them a lot. I learned a lot about myself and how much I have in me. I wasn’t expecting what happened today to happen and I will learn from it.”

Ryu claimed a second major title, but admitted that victory did not feel right. “I cannot believe the situation. I didn’t even check the leaderboard, Lexi was playing so well. I didn’t expect it,” she said. “It hurts me as well, it is a weird feeling but at the same time I am proud of myself.”