Lee Westwood equalled his previous best round at the US Masters with a five-under 67 on Thursday's opening day.
Westwood, who leads South Africa's Louis Oosthuizen and Peter Hanson of Sweden by one shot, was understandably delighted with his opening 18 holes at Augusta.
"There was no weakness out there in my game," Westwood said. "I hit it close, hit a lot of fairways and rolled in some nice putts.
"I've been playing well all year so I was pretty confident. But trying not to let myself get carried away.
"I just wanted to come out and start steady and strong and play my way into the tournament, which I've done."
There were no low-scoring first rounds for pre-tournament favourites Tiger Woods (72) and Rory McIlroy (71).
Four-time champion Woods blamed some old habits creeping into his new-look swing as errant drives on the second and 18th needed drops from unplayable lies.
"I hit some of the worst golf swings I've ever hit today, and that's all right," said the world number seven, who won the last of his 14 majors in 2008.
"I just hung in there and grinded my way around the golf course and stayed very patient, stayed in the moment. I got a lot out of that round."
McIlroy, 22, looking to atone for last year's final-round collapse when leading by four, began ominously with a double-bogey six.
The US Open champion fought back to one under by nine, but on the 10th, the hole that sparked his trouble last year, he drove off the fairway on the right after overcompensating for the left-hand trees that caught his ball 12 months ago.
Though he rescued a par, he bogeyed the 11th and found the creek in front of the 13th green in two and ran up a bogey six. But he birdied 17 and 18 to end the day one under.
"I'm a lot more pleased coming off the golf course than if I had finished par and to come off under-par is pleasing," the Northern Irishman said.
"My perseverance and patience paid off and it was nice to finish as I did, but I'm surprised someone didn't go lower than five today."