PGA: PGA Championship - First Round

Martin Kaymer tees off on the 9th during the first round of the 2020 PGA Championship golf tournament at TPC Harding Park. 

SAN FRANCISCO - Martin Kaymer did not expect much coming into the PGA Championship given how little he has played this year but rust did not seem to be a factor after he carded a four-under-par 66 to sit a stroke back of first-round leader Jason Day.

The former world number one, who missed the cut in his only start of the year at last week's Barracuda Championship, stumbled early at San Francisco's TPC Harding Park with a bogey on his second hole.

However, it was a different story after the turn as the German reeled off two birdies and an eagle over a four hole stretch to climb the leaderboard.

"My expectations were very low, to be honest, because I didn't really know where my game was at," he told reporters.

"Obviously I knew I was playing okay, but on a golf

course like this, okay play doesn't really get you far."

Seeking some inspiration, he said he pulled up the footage of his 2014 U.S. Open victory in North Carolina.

"Definitely that video from last night of me winning the U.S. Open helped me to believe that my putting was good enough and that my ball-striking was good enough," he said.

"Even though it's a few years back, but it's always nice to remember those moments and feel the same that you felt that day."

In addition to his U.S. Open win, the 35-year-old also won the PGA Championship in 2010, a video he said he watched while under lockdown in Germany due to the COVID-19 pandemic.

"I like to go back to those moments," he said.

"I know you shouldn't live in the past, but if the past can help you in the present moment, I'll take it."

Kaymer will be grouped with Day and Jason Dufner again on Friday for the second round of golf's first major of the year.

(Editing by Peter Rutherford)