SPRINGFIELD, N.J. — This is what kind of day it was for Robert Streb: He tied a PGA Championship record for the lowest score through 36 holes and no one noticed or congratulated him on it. No big deal. It was not nearly the best history he made on Friday, witnessed by the sound that accompanied his birdie on the final hole.

“It was pretty noisy, for the 15 people who were out there,” he said with a smile. “They obviously knew what was going on.”

They knew that Streb, finishing his rousing round on the par-4 ninth with his third birdie in his last nine holes, had just shot 63 — tied for the best score ever shot in a major.

“They made a little racket when the putt went in,” said the 29-year-old from Chickasha, Oklahoma, who ended the second round at Baltusrol Golf Club tied with Jimmy Walker for first in the 2016 PGA at 9-under par. The two of them were tied historically with seven golfers who previously had shot 131 through the first two rounds of a PGA, most recently 2013 champion Jason Dufner.

But that took a back seat to the magic number, 63. Counting Streb’s 7-under-par round on Friday, it has been done 30 times in history by 28 golfers (Greg Norman and Vijay Singh each did it twice). It has been accomplished four times at Baltusrol (more frequently than anywhere else): Jack Nicklaus and Tom Weiskopf in the 1980 U.S. Open and Thomas Bjorn in the 2005 PGA.

“I saw it the other day,” Streb said, referring to the list. It went through his mind as he watched his final putt. “I was waiting on it to break, waiting on it to break and it finally turned there at the end. But it was a great round. Happy to be part of the 63 club.”

With Baltusrol having been softened by more than an inch of rain Thursday night into Friday morning, who’s to say that someone might not start his own 62 club before the weekend is over? The group near the top features defending champion Jason Day, who shot 65 with five birdies in a six-hole span and is tied for third at 7-under with Emiliano Grillo. One stroke behind them is Henrik Stenson, who won the British Open 13 days ago with his own 63.

How low can they go? “I think it’s all course condition,” said Walker, who followed his 65 Thursday with a 66. “I didn’t know of a scoring record or tying or anything . . . Everybody out here is really good and when there’s not a lot of wind, guys can pick apart a golf course pretty easily. And that happens week in and week out.”

Not for Streb, though. Like Walker, he entered the PGA in a season-long slump. He has missed the cut in all three previous majors and has not had a top 10. Friday was the first time in a long time that he regained the form that won him the 2015 McGladrey Classic.

“Just kind of tweaked my swing a little bit, and I don’t know a better way to put this, but it kind of feels like my golf swing again,” he said, adding that he entered with modest goals. “Just to see if I could play some good golf and have some fun.”

By day’s end, he had the fun of being the first in his player-caddie pairing to recognize the possibility at hand.

“I’m not sure he realized it until he paid attention to the board there on 9,” Streb said of his caddie. But then the crowd knew and now everyone at Baltusrol will know to have their eyes open for history.