Updated at 9:21 a.m. ET
Oosthuizen, the 2010 Open champion at St. Andrews, was at 2 over par entering the 14th and left at level par. He finished with an even-par 71. He's the first person in the last 30 years to make an ace in two different majors in the same year. Oosthuizen also aced the par-3 16th hole in the final round of the Masters.
"[J]ust a solid 6-iron.," Oosthuizen said of his hole-in-one. "I was thinking a little 5 [iron] maybe and caddie convinced me it's just a normal 6-iron. It will easily cover the front and just make a good swing. Don't try anything hard, and I did that. So I've got to give him a little credit for that, for talking me into that 6-iron."