Video footage showed that Ancer "unknowingly" touched the sand in a bunker on the 15th hole on Thursday.
In a statement from James B. Hyler, Jr., chairman of the Augusta National's competition committee, because the touching of the sand was "deemed visible to the naked eye" and the world No. 31 signed his scorecard, a penalty was handed out.
"On the 15th hole during Thursday's first round, Abraham Ancer unknowingly touched the sand before making his third stroke from the greenside bunker," the statement said.
"After Mr. Ancer had signed his scorecard and exited the scoring area, video evidence was reviewed by the Committee regarding a potential breach of Rule 12.2b(1), which states that touching sand in a bunker right behind the ball results in a penalty. The touching of the sand was deemed visible to the naked eye. Had this not been the case, the video evidence would have been disregarded and a penalty would not have been applied."
Having finished with a bogey six on the par-five 15th hole, it became a triple-bogey eight with the penalty and his one-over 73 became a three-over 75.
"I was just informed that I have been assessed a 2 stroke penalty for unintentionally grazing the sand in my backswing on hole 15," Ancer wrote on Twitter on Thursday, accompanied with a video of his transgression. "While I'm gutted, I can't wait to get after it tomorrow."