Irish Open champion Jon Rahm holds a three-shot lead at eight-under-par into day two of the WGC FedEx St Jude Invitational.
The Spaniard sank a run of long-distance putts in and carded eight birdies for a bogey-free first round in Memphis - it's also the joint best round of his career.
America's Patrick Cantlay and Bubba Watson, Shugo Imahira and Hideki Matsuyama of Japan and Australia's Cameron Smith lead the chase at five-under.
Rahm says he's been able to quickly adjust to the greens after last weekend's Open at Royal Portrush.
"I think it's just imprinted in memory...It just felt good. Once you come into the tournament, and hit a few putts, for the most part it's like you're back here. To me, it's always easier to adjust to quick greens than going to slow greens.
“I didn't do anything Monday or Tuesday, I just rested and stretched at the hotel, in the room.
“And then yesterday I came with the plan of playing 18 holes. I putted and warmed up, and after four holes… I was dead. I couldn't swing properly. I was really tired, so I just decided to just finish the round of nine holes, eat and just putt a little bit and go.
“I tried to put a little emphasis on being rested and it paid off today. Obviously I have three more days to go and hopefully the battery lasts, but that was the main deal for me.”
Dustin Johnson, who won last year's St Jude Classic on the same course, carded a one-under opening-round 69, as did Rory McIlroy, who missed the cut by one shot at the Open.