Golf: Spieth serves notice he's still the Master at Augusta

Augusta, United States - A year after his wire-to-wire Masters triumph, Jordan Spieth is still making history at Augusta National and served notice that rivals will have to pry the green jacket off him.

The world number two matched the lowest opening round by a defending Masters champion on Thursday, firing a six-under par 66 to seize a two-stroke lead after the first round at Augusta National.

"I put it up there with one of the best rounds I've played," Spieth said.

Not since Jack Nicklaus in 1966 - the year he became the first back-to-back Masters winner - had a defending champion owned the outright lead after the first round, but the 22-year-old American matched the feat and could join Nicklaus, Tiger Woods and Nick Faldo as the only back-to-back winners in Masters history.

After matching Woods for the lowest 72-hole score in Masters history at 18-under 270 last year, Spieth solved cool and breezy conditions for a bogey-free round that might have been superior to his opening 64 last year.

"The way I was playing was better a year ago, but the score that came out of the round may have been more impressive today," Spieth said. "Got a lot out of the round with what I felt like was kind of average-ish ball striking.

"It was extremely special to stay bogey-free on a day like today at the Masters." Spieth, whose champion's opening 66 matched that of Spaniard Jose Maria Olazabal from 1995, became the first golfer to lead the Masters for five rounds in a row and the first to begin his Masters career with nine consecutive rounds at par or better.

"Being in this position is really cool," Spieth said.

"We just stay patient with what we're doing. We know how to win this tournament, we believe in our process and if the putts are dropping, then hopefully it goes our way."

Spieth was greeted at the tee of the par-3 12th by a standing ovation from the huge crowds that gather to overlook the famed three-hole stretch known as "Amen Corner." "It was one of the coolest moments I've ever had here," Spieth said.

"Just to see everyone start to rise, it was really cool to feel like you belong as the Masters champion. Not that I needed any more reason, but just the gallery recognises you've won here and this is a special place to you. I thought it was an awesome moment."

English playing partner Paul Casey, who shot 69, was impressed with how he coped with the winds that swirled through the Georgia pines.

"That was a flawless round of golf," the Englishman said. "When he got into trouble... he bailed out in the right place and what could have been an error he turned into a wonderful par save. It was great to have a front-row seat to watch that."