Martin Kaymer admits it is a "little sad" that his victory in the 2010 US PGA Championship has been overshadowed by the last-hole incident involving Dustin Johnson.

But the two-time major winner believes Johnson could have the last laugh by finally claiming his first Major title five years on at Whistling Straits.

Johnson was famously penalised two shots on the 18th hole in the final round after it was ruled he had grounded his club in a fairway bunker before hitting his second shot.

However, even without the penalty Johnson would not have won the title outright after a bogey five had seemingly left him tied with Kaymer and Bubba Watson.

"It's a little sad that every time we talk about the PGA Championship here it's like that Dustin threw it away," Kaymer said. "Everybody still thinks that he would have won the tournament outright.

"He would have been in the play-off and it would have been still Bubba, Dustin and me. And that's the only thing that's a little strange about the whole thing.

"Obviously it was sad to see. You fight for something so hard and then things like this happen on the 72nd hole. You don't wish that on anyone.

"It was very unfortunate for him, but on the other hand, knowing what kind of player he is, he will be in that position again. If it would have happened to a player who will never be there again, then you feel very, very sorry. For Dustin, you know he's going to be there again and he will win a major eventually.

"I think Dustin will have a good chance this week to win here. It would be quite a funny story if he would raise the trophy on Sunday."

Johnson had blown a three-shot lead in the final round of the US Open a month earlier and is still seeking a first major title after three-putting the 72nd hole of this year's US Open at Chambers Bay to finish a shot behind Jordan Spieth.

In contrast, Kaymer led from start to finish to win the US Open at Pinehurst in 2014, a month after winning the Players Championship - the so-called 'fifth major' - in the same style at Sawgrass.

As for his major breakthrough here in 2010, Kaymer revealed his focus had actually been on a team event rather than individual glory.

"I was very surprised that I was in the play-off, because my goal was not really winning the PGA Championship when I played the last round," added the 30-year-old, who beat Watson in the three-hole aggregate play-off.

"For me the main goal was to get into the Ryder Cup team back then. And obviously after my round on Sunday I knew it was enough, so I was very happy about it. I didn't even think that there might be a play-off.

"And I signed my card and all those things happened and all of a sudden I was standing on the 10th tee again."