AUGUSTA (Georgia) • The methodical Bryson DeChambeau, who last week put himself through a 14-hour practice session to decipher the effect of what he called the "spin loft curve" of his wedges, was asked late on Thursday to assess the final nine holes of his opening round at the Masters.

The 25-year-old, who birdied six of those nine holes, including the final four, responded with neither a technical term nor a scientific one.

"Magical," he said.

On a favourable-weather day that produced 28 rounds under par, DeChambeau was one of the last competitors on the Augusta National Golf Club grounds, and he played as if enchanted by a spell.

His last full shot to the 18th hole seemed destined to roll into the hole for an eagle until the flagstick deflected it.

He instead tapped in from about two inches for a final, stress-free birdie, giving him a six-under 66 and a slice of the lead alongside fellow American Brooks Koepka.

It was just his ninth competitive Masters round and the first time he had recorded a score in the 60s.

DeChambeau freely conceded that in the past, he felt uncertain in the sanctified setting of golf's most tradition-laden event but, on Thursday, he showed a newfound maturity.

The world No. 6 said: "It was understanding how to control certain emotions on the golf course.

"Just from a nerve perspective, being comfortable in different situations and being able to say, 'I can do this, this is not a problem'."

DeChambeau was far from the only top golfer firing away at greens softened by rain earlier in the week.

Koepka also surged late in his round to remind the field, should anyone forget, that he had won three of the past seven Major events, two with record scores.

After carding "probably the best ball-striking round I've had in a Major championship", the world No. 4 declared: "I enjoy the big stage. It's what you're remembered for."

His bogey-free day was all the validation he needed after the build-up to the Masters included criticism of his decision to lose almost 11kg, with Koepka insisting he "did not care what anyone else says as I'm doing it for me".

One stroke off the lead was five-time Major champion Phil Mickelson, who had two bogeys and five birdies on the back nine, while second-ranked Dustin Johnson was two strokes behind the leaders.

Mickelson, 48, who is bidding to eclipse Jack Nicklaus (46) as the oldest Masters champion, stormed home with five birdies over the last seven holes.

For most of the early part of the round, the focus was on Tiger Woods, who was tied for the lead with only a few holes left in his first round. The former world No. 1's surge had the Augusta National galleries in full throat, especially after he made an improbable birdie from the thick trees left of the 14th hole.

While he could not maintain the momentum he had built, finishing with a 70, Woods recalled he had shot the same first-round score when he won the tournament in 1997, 2001 and 2002.

The 14-time Major winner added: "I've shot this number and won coats, so hopefully, I can do it again.

"I feel very good. I played well and I controlled my golf ball all day.

"I did all the things I needed to do today to post a good number... Overall, I was pleased."

AGENCE FRANCE-PRESSE, NYTIMES

MASTERS

Day 3: Singtel TV Ch114 & StarHub Ch208, tomorrow, 3am