Rory McIlroy acknowledged he had been saved by his short game at Augusta on Thursday, while expressing amazement at the seven-under 65 that gave Charley Hoffman a four-shot lead.
McIlroy, the highest-ranked player in the field following Dustin Johnson's late withdrawal through injury, made a sluggish start to his opening round and was three over through eight despite holing clutch par putts on the fourth and seventh.
However, a succession of up-and-downs at the start of the back nine gave the Northern Irishman momentum as the day's strong winds started to ease somewhat.
And birdies at 13, 15 and 16 - the latter courtesy of a stunning tee shot to around three feet - ensured McIlroy posted a 72 to share 12th at level par.
Having spent much time focusing on his chipping and putting when he was sidelined by a rib injury earlier this year, McIlroy said: "My short game really saved me today - especially 10, 11, 12 were huge.
"To get those three up and down, not that I had much momentum, but to at least have something going into that stretch where I could pick up a couple [was significant].
"I was thankfully able to birdie the two par fives [13 and 15] and another one coming in, and even par was a great score today. I'm really happy with that.
"I gritted it out and I would have ripped someone's hand off for a 72 on the 10th tee. I would have struggled to put together a back nine like that in previous years, but I've done the work on the short game and I believe that I'm doing the right things.
"I just didn't want to give up, I wanted to put my head down, show a bit of grit, a bit of determination and I was able to do that."
Asked what went through his head when he looked up at the scoreboard to see a leading score of seven under, McIlroy succinctly replied: "Holy s***!"
He added of Hoffman's remarkable round: "It was unbelievable, just incredible. I thought if anyone broke 70 today that would be an unbelievable score, and then to see what Charley did over the last six or seven holes was just incredible. I mean it's some golf - I'm walking off there, after my start, ecstatic with a 72 and he's posted 65.
"But, as they say, they don't give green jackets out on Thursdays and there's no winning post there, so I think I'm in a good position with three rounds to go and we'll see how it goes."
A bogey-bogey finish saw Jon Rahm fall one behind playing partner McIlroy on his Masters debut.
The highly-rated Spaniard said: "I feel like I played better than the score shows, but it's still a great score. Just a couple of misses towards the end and a couple of missed putts early makes it a little worse score than what I feel like."