Augusta - Reigning Open champion Jordan Spieth will draw upon memories of his epic 2015 Masters victory and his nightmare 2016 back-nine Sunday collapse in trying to win another green jacket.
The 24-year-old American birdied five consecutive holes starting on the par-5 13th in firing a six-under par 66 and seizing a two-stroke lead after Thursday's opening round of the Masters.
Fourth-ranked Spieth says his best and worst memories at Augusta National will inspire him over the final 54 holes.
"I'll always have demons out here, but I'll always have a tremendous amount of confidence," Spieth said. "Once you win here, you have an advantage over anybody who hasn't. And there can be positives and negatives to both the demons and the confidence.
"So it's just about playing the golf course for what you get, recognizing what the tendencies are this course brings and what my own tendencies are when under the gun."
Spieth did match the Masters tournament record of 18-under 270 set by Tiger Woods in 1997 to win three years ago.
But two years ago he squandered a five-shot lead on the final nine holes - a quadruple-bogey at the par-3 12th helping England's Danny Willett win the green jacket, Spieth having to put in on him.
Spieth added the Claret Jug last year for his third major crown, a haul that also includes the 2015 US Open, and said he felt the Sunday tension on Thursday but responded with a run of five straight birdies on the back nine before a closing bogey.
"Today I felt the Sunday-type pressure of leading the Masters on the middle of that back nine, and adjusted extremely well," Spieth said.
Spieth, who eagled the par-5 eighth after bogeys at the fifth and seventh holes left him on level par, says being in front helps make Augusta National play easier, all 2016 evidence aside.
"If you get off to a good start, you're in control of your own fate, versus needing a little bit of help," Spieth said.
"This course is a lot easier to play if you feel like you can just hit the centre of the greens and wait for your chances. You want to take that approach starting out, but if you start well, it's easier to stick to that game plan."
Spieth warns that the course will send everybody's scores skyrocketing on the weekend and players have to prepare for that mentally.
"On the weekend, it backs you up. It backs everybody up," he said. "And you've got to be prepared for that.
"So I imagine there will be plenty of times, if not from early on tomorrow, that I don't lead this tournament anymore. Just things happen in this sport. I'm going to try and control what I can control and that's about it."
Spieth credited iron shots as much as putts to his crucial back-nine birdie binge.
"It's nice that I was able to shoot a score like this," he said. "I felt like I putted well, but I didn't putt amazingly well. I just hit some really solid iron shots on that back nine to go with just some solid, inside of 10-12 feet, putting."
While most players would see the 72-hole showdown as one-quarter done, Spieth says he looks at the Masters as a six-round fight.
"This tournament often feels like there's six rounds with how the weekend grind is," Spieth said. "Really any major. I feel like I'm kind of one round down out of six, so I'm not getting ahead of myself. It's just it was a really good start."
Complete first-round scores on Thursday from the 82nd Masters at par-72 Augusta National Golf Club (a- denotes amateur):
66 - Jordan Spieth (USA)
68 - Tony Finau (USA), Matt Kuchar (USA)
69 - Adam Hadwin (CAN), Li Haotong (CHN), Henrik Stenson (SWE), Charley Hoffman (USA), Patrick Reed (USA), Rory McIlroy (NIR), Rafael Cabrera Bello (ESP)
70 - Bernd Wiesberger (AUT), Zach Johnson (USA), Marc Leishman (AUS), Phil Mickelson (USA), Rickie Fowler (USA)
71 - Vijay Singh (FIJ), Satoshi Kodaira (JPN), Cameron Smith (AUS), Xander Schauffele (USA), Louis Oosthuizen (RSA)
72 - Francesco Molinari (ITA), Kyle Stanley (USA), Charl Schwartzel (RSA), a-Doug Ghim (USA), Fred Couples (USA), Kevin Kisner (USA) Tommy Fleetwood (ENG), Justin Rose (ENG)
73 - Ted Potter Jr. (USA), Brian Harman (USA), Daniel Berger (USA), Pat Perez (USA), Jason Dufner (USA), Hideki Matsuyama (JPN), Branden Grace (RSA), Tiger Woods (USA), Bubba Watson (USA), Jimmy Walker (USA), Russell Henley (USA), Thomas Pieters (BEL), Dustin Johnson (USA)
74 - Austin Cook (USA), Wesley Bryan (USA), Ryan Moore (USA), Jose Maria Olazabal (ESP), Bryson DeChambeau (USA), Paul Casey (ENG), Martin Kaymer (GER), Justin Thomas (USA), Sandy Lyle (SCO), Ian Poulter (ENG), Bernhard Langer (GER), Tyrrell Hatton (ENG), Alex Noren (SWE)
75 - Jason Day (AUS), Kim Si-woo (KOR), Patrick Cantlay (USA), Matthew Fitzpatrick (ENG), Danny Willett (ENG), Adam Scott (AUS), Jon Rahm (ESP)
76 - Angel Cabrera (ARG), Mike Weir (CAN), a-Joaquin Niemann (CHI), Yuta Ikeda (JPN), Brendan Steele (USA), Patton Kizzire (USA), a-Doc Redman (USA), Billy Horschel (USA), Chez Reavie (USA), Larry Mize (USA), Webb Simpson (USA)
77 - Shubhankar Sharma (IND), Dylan Frittelli (RSA), Kevin Chappell (USA), Jhonattan Vegas (VEN), Yusaku Miyazato (JPN)
78 - Trevor Immelman (RSA), Mark O'Meara (USA), Ross Fisher (ENG), Gary Woodland (USA)
79 - Lin Yuxin (CHN), Ian Woosnam (WAL), Kiradech Aphibarnrat (THA)
81 - Sergio Garcia (ESP), a-Matt Parziale (USA)
86 - a-Harry Ellis (ENG)