South African Charl Schwartzel leads the Memorial Tournament presented by Nationwide Insurance after an opening seven under par 65 at Muirfield Village.
The former Masters Tournament champion overcame a double bogey at the eighth and a dropped shot at the 13th with ten birdies.
At seven under Schwartzel leads by one from American Scott Piercy, with Josh Teater, Kyle Stanley, Russell Henley and Charlie Wi on five under.
Swede Robert Karlsson and Schwartzel’s compatriot George Coetzee were both round in 69 to be lie inside the top ten, with Justin Rose and World Number One Tiger Woods among those on two under.
Schwartzel said: "I felt like I played really well, just ticking the ball over and got it to eight under.
"I just had a bad one on number eight, made a double (bogey). And that was the very worst I played all day.
"That was one of the best rounds of the year; I hit the ball beautifully, I shot it so well and I gave myself so many chances."
