Augusta - Jordan Spieth played on Sunday's last round of the Masters like he didn't have a hope of winning, and lo and behold, gave himself a chance at another green jacket. 

The reigning British Open champion, who began the day nine strokes adrift of eventual winner Patrick Reed, matched the low final round in Masters history with an eight-under par 64 and came within a closing bogey of matching the 18-hole course record of 63. 

"In general this round was fantastic," Spieth said.

"I mean nobody's going to have a great Sunday every year at Augusta National." 

He finished third on 13-under 275, two back of Reed and one behind runner-up Rickie Fowler. 

Spieth, also the 2015 US Open champion, shared second at the Masters in 2014 and 2016, the runner-up efforts sandwiched around an epic 2015 triumph with a 72-hole record matching 18-under 270. Spieth was fourth entering last year's final round before shooting 75. 

"To be able to have a chance to win this tournament five years in a row is really, really cool and that's how I'm going to take today," Spieth said. 

The 24-year-old American knew no winner had ever recovered from more than eight strokes down in the final round to win. 

In fact, had he won, Spieth would have had the second-best comeback in major golf history after Scotsman Paul Lawrie's 10-shot Sunday rally to win the 1999 British Open. 

So Spieth adopted a laid-back attitude and swears he never looked at a leaderboard to see his charge into a share of the lead on the back nine. 

"Didn't look once. That was my plan," he said. "Go out and just have fun. Don't worry about the golf tournament itself, worry about playing Augusta National. I heard roars. I knew someone was playing well. With eight people ahead of me starting the day, to get that much help and shoot a fantastic round was nearly impossible. 

"But I almost pulled off the impossible." 

Spieth fired nine birdies, including two to open the front nine and two more to close it, then added back-to-backers at his nemesis par-3 12th and par-5 13th, plus the par-5 15th and par-3 16th to share the lead before his eight-foot miss to take bogey at 18. 

"I had no idea. When I finished and I looked at the board I could have been in the lead by two and I could have been down four. And neither one would have surprised me," Spieth said. 

"It was, 'Don't worry about the tournament at all, even when I got to 9-under, I still didn't care. It was working for me the way I was doing it, so there was no reason to change anything." 

Spieth's back-nine charge began with his toughest putt of the day, a 27-footer for birdie on the same 12th hole where he took a quadruple-bogey 7 in 2016 to squander his hopes at a wire-to-wire Masters title repeat. 

"What we did on 12 today was really cool," Spieth said. "That hole, even when I didn't hit it in the water in previous years, I three putted in 2015 for bogey. 

"So to play a disciplined shot, probably the most pressure-packed shot I've ever hit, and my history there, to stand in that kind of pressure and hit the shot to the safe zone to knock that putt in was massive for me going forward." 

He birdied three of the next four holes and would eventually join Australia's Greg Norman as the only players to record two 64s at Augusta National.