Masters leader Jordan Spieth says he is just "one round down out of six" such is the difficulty of playing at Augusta and is ready to have to grind out victory over the coming days.

Spieth's love affair with the Masters continued in round one on Thursday, as a stretch of five birdies between the 13th and 17th holes saw the three-time major champion surge into the lead.

He toiled at the final hole before a stunning wedge shot limited the damage to a bogey, and a six-under-par 66 was enough for Spieth – the 2015 champion – to lead by two shots.

Spieth's showing was reminiscent of the stunning opening 18 holes he played three years ago where a 64 contributed to his wire-to-wire victory that matched the record low score for victory.

The 24-year-old is refusing to look too far ahead of himself after setting an early marker, but recognises he is now in control of his own Masters destiny.

"I think this golf course is a lot easier to play if you feel like you can just hit the centre of the greens and move from there and wait for your chances," he said.

"It's easy to say that. You kind of want to take that approach starting out, but if you start well, it's easier to stick to that game plan.

"I shot two rounds in the 70s and tied a scoring record here one year. It just shows that on the weekend, it [low early rounds] backs you up.

"It backs everybody up, and you've got to be prepared for that.

"I think quick starts are important in any event. It's not unique to the Masters at all. It's any tournament. If you get off to a good start, you're in control of your own fate, versus needing a little bit of help.

"This tournament often feels like there's six rounds with how the weekend grind is.

"I feel like I'm kind of one round down out of six, so I'm not getting ahead of myself. It's just a really good start."

Asked if his quick start means he can dictate the outcome of the tournament, Spieth replied: "Technically, yes.

"For me, again, it's the first round out of six rounds. In my mind I try and look at it from that perspective that lots change.

"To go wire to wire in a tournament is a rare occurrence in any tournament, anywhere.

"So, I imagine there will be plenty of times, if not from, you know, early on tomorrow that I don't lead this tournament anymore.

"Just things happen in this sport and I'm going to try and control what I can control and that's about it."