NEWTOWN SQUARE, Pa. — You’re not alone if you are surprised to see Martin Kaymer at the top of the leaderboard after the opening round of the PGA Championship.

Consider this:

“I’ll tell you a funny story,’’ Kaymer said after shooting a 3-under-par 67 at Aronimink. “On Tuesday evening we had the champion’s dinner, and there was a gentleman sitting next to me from the PGA of America and he asked me if I still play.

“And I said, ‘What do you mean?’ He said, ‘Well, are you playing this week?’ And I said, ‘Yeah, that’s why I’m here. I’m not flying from Europe to here to have a New York strip with you guys. Of course I’m playing.’

“And that really motivated me. So it was a good start to the week. Again, I really enjoy Aronimink Golf Course. It really suits my eye. It’s a very fair test. Great for the PGA Championship. It’s fun to play and I look forward to hopefully have another three good days.’’

People forget how accomplished the 41-year-old German is, having won a U.S.…