Both before and after his last stroke, Justin Thomas may have been the calmest person around Waialae Country Club’s ninth green Thursday.

Thomas had put together a remarkable opening round to the Sony Open in Hawaii to that point and surveyed an eagle putt just inside of 15 feet from history.

“I wasn’t too nervous over the putt. I was just more focused on trying to make the putt,” Thomas said.

He coolly rolled his ball — soon to be a keepsake — into the cup to reach one of golf’s magic numbers with a tournament-record 11-under-par 59.

The eagle drew fist pumps from close friends and playing partners Jordan Spieth and Daniel Berger after Thomas punctuated the eighth round of 59 or better in PGA Tour history.

“The coolest part for me was how excited they were for me on 18,” Thomas said. “To do that with two of your best friends out here.

“I thought about it going up to the green. I’m like, ‘If I make it, what am I going to do?’ It’s not like winning the tournament. It’s like, ‘Hey, unbelievable round, you have three days left to try to play well.’ So I didn’t really know how to react. I never had a putt on the last hole on a Thursday mean that much.”

With Waialae’s winds conspicuously absent, Thomas cut through the vog to bookend his round with eagles with eight birdies and a bogey in between and surpassed the tournament’s 18-hole record of 60 set by Davis Love III in the second round in 1994.

Even so, he’s a long way from claiming his third victory of the season and second in the state after winning the SBS Tournament of Champions on Maui last weekend.

Conditions remained calm in the afternoon and Hudson Swafford played his second nine at 29 and enters today’s round three strokes behind Thomas after signing for a 62. Rory Sabbatini, who has three top-10 finishes in the tournament, matched his best Waialae round with a 63.

Thomas, 23, fired a 61 in the second round two years ago, but hadn’t gone under 70 in his next four rounds at Waialae and missed the cut last year.

“I know this course if you drive it well you can play really well. It’s the hardest fairways to hit on tour I think and the greens aren’t big,” Thomas said.

“The biggest thing is just getting it in play because I can just hit a lot of 2-irons out here and then I’m having short irons in, and I felt comfortable enough with those that I could hit my numbers.”

Statistically, Thomas hit eight of 14 fairways and 14 of 18 greens in regulation and took 23 putts to become the youngest player to join the 59 club.

Thomas began his day by holing out a wedge for eagle on the 10th from 34 yards out. He followed with his lone bogey of the day and birdied five of his last six holes on the back nine to make the turn at 29.

He kept the standard bearers reaching for red numbers with birdies on Nos. 1 and 2 and got to 9 under with his eighth birdie of the morning after sticking his tee shot on the par-3 fourth hole inside of 6 feet.

“Being 9 under through 13 I was like, ‘This is a great opportunity.’ You don’t get it very often in golf,” Thomas said.

But when birdie putts on Nos. 5 and 7 — “two of the best putts I probably hit today” — stayed out of the cup, “I was kind of saying to myself, “You know, maybe this isn’t meant to be.”

He pulled his tee shot on No. 8 under the trees right of the fairway. He had to pull out one of the signs marking a fairway crossing to clear his line to the green and his low 7-iron ran into a bunker. After escaping the sand, he dropped a 10-footer to save par, much to the relief of his father and golf teacher, Mike Thomas.

“The most nervous I was was the par he made on the 17th hole (of the round),” Mike Thomas said. “That was huge because if you don’t make that it’s over.”

His drive on the par-5 ninth went into a bunker to the left of the fairway and he initially thought about taking a wedge out of the bag before Berger, hitting from the same bunker, hit 4-iron onto the green.

“I’m like, ‘He just did it.’ This isn’t a time for me to lay it up,” said Thomas, who then took 5-iron.

“I absolutely flushed it,” he said. “The wind died down a little bit for me and it flew up there about pin-high and I rolled it in.”

Before taking his seat in the interview room, Thomas tossed the ball to his father, a club pro at Harmony Landing Country Club in Goshen, Ky.

While he coached Justin since the youngster could walk, he didn’t exactly hover through Justin’s early years.

“Our relationship and our instruction … (was) more, ‘Hey just come and get me if you need something.’ I didn’t stand out there all the time,” Mike Thomas said. “I taught him to know his own game, to not need me.”

Mike Thomas didn’t get to see his son’s first two tour victories, but Justin’s given his family a show during their trip to Hawaii with his win on Maui and Thursday’s round.

“I didn’t see either win in Malaysia so last week was pretty cool and then this week … very fortunate for sure,” Mike Thomas said.