Playing in the second last group of the day, the 2015 champion reeled off five consecutive birdies from the 13th to the 17th and, despite a closing bogey, signed for a 6-under 66.
Spieth leads over Matt Kuchar and Tony Finau, whose participation in the tournament looked in doubt after he injured his ankle while celebrating a hole-in-one in the previous day's Par-3 Contest.
“I had phenomenal up and downs on 10, 11 and 12 that kept the momentum going,” said Spieth.
"My hand was slipping a little bit as it gets a little sweaty out here and I switched gloves on 13 fairway and I started pin seeking after that. I had a lot of good numbers though where I can hit nice full shots and that makes a big difference here at Augusta.
“It is round one and I know as well as anybody that anything happens here at Augusta National and I am not going to get ahead of myself. It is just about riding the momentum from last week and off this first round.”
There was a sharp improvement in Spieth’s more recent putting form and he explained afterwards how that tide had turned.
"I am just trying to have my eyes match my putter. The last six months or so I have been kind of a little bit off and have not been able to trust my reads or trust my stroke and I put a lot of work in over the last ten days or so and started to see some results the last week which is sometimes enough momentum to shoot some good rounds.”
The rollercoaster of emotions that is the game of golf is hardly better illustrated than has been the case over the last 24 hours at Augusta National.
Following his bizarre Par-3 Contest accident, Finau declared himself ready to play at 7am local time on Thursday, having had treatment and elevation of his ankle overnight. Another assessment and MRI this morning essentially cleared him to play and the results were spectacular.
“No way, no way,” said Finau when asked if he could have imagined a round of 68 after a dramatic 24 hours.
“After the Par-3 Contest and the way I felt this morning it wasn’t great so there was no way I felt I would be in this position.
“I was quite embarrassed (yesterday). The last thing I wanted to do while celebrating a hole-in-one was to be pulled out of here on a stretcher.
“The pain was excruciating but this is a moment I dreamed of my whole life and the possibility of playing here against the best players in the world slipping away was tough.
“To be in this position I'm at now; when I woke up this morning, nothing short of a miracle if you ask me. I could barely put any pressure on it. I could barely walk. But obviously, after the MRI we had, you know, there was no real damage. So at that point, at about [8am] this morning, I knew I was going to play.”
When Finau finished his round of 68, he led by one but was quickly caught and passed by Spieth.
An eagle from 15 feet at the par-five 8th moved the American to 2 under before he caught fire late in his round.
While that rush of birdies was important it was perhaps his two par saves from awkward positions on the 11th and 12th that retained the momentum and allowed him to build on the solid start he had made.
Kuchar bounced back from a slow start to play the final nine in 5 under and was clearly delighted to do so.
"The last two weeks have been good, and certainly that helps the confidence. Golf is a fickle game, and I think playing good golf breeds more good golf. I've felt good the last few weeks and came in looking forward to this week.
“You always hope to be able to peak at the right times; this being the right time, but one of those things, it's hard to control. I certainly was awfully glad to kind of right the ship from being 2‑over par through seven holes and end up posting a good round of golf."
A total of seven players are tied for 4th namely Henrik Stenson, Li Haotong, Patrick Reed, Charley Hoffman, Adam Hadwin, Rafa Cabrera Bello and Rory McIlroy who is of course chasing a career Grand Slam this week.
McIlroy paid tribute not so much to his brilliance today but his grinding late in the round when he saved pars at closing holes.
“Probably those last three holes," he said when asked the highlight of his round. "It's not always the birdies that stick out in your mind. That downhill left‑to‑right that I had on 17 was nice to see that go in. But I drove it well. Everything was really solid. And if I can continue to play like that over the next three days I'll be pretty close.”
The Australians are headed by Marc Leishman whose round of 70 was produced in the company of Tiger Woods. Leishman hit the lead when he moved to 4 under through 14 holes but a double at the dangerous 15th took the gloss off something even more special.
Woods managed a round of 1 over 73 but the talking point of the day, other than the brilliance of Spieth and the heroics of Finau, was the 'Tin Cup' episode of the defending champion Garcia whose took a 13 at the par-five 15th after hitting five consecutive balls into the water.
JORDAN'S SPIETH 'CHICKEN WING' ACTION
Want video tips delivered straight to your inbox? Subscribe to iseekgolf.com newsletters.