"Should have been eight," said Kaymer, who three-putted from inside 20 feet on the par-5 17th and settled for par.
Billy Horschel shoots 63 to take lead into BMW Championship final round →
"I don't realize what happened," Kaymer said. "I just won my first major. I've got goose bumps just talking about it."
Kaymer wins PGA Championship in playoff →