Open champion Collin Morikawa leads the way with a pair of five below next to Joel Dahmen after a magnificent second round of 66, with reigning U.S. Open champion Jon Rahm and four times winner of the major Rory McIlroy to a shot.
Master champion Scottie Scheffler was part of the group once again, with Englishman Matt Fitzpatrick three below the pace and two below.
McIlroy had run the risk of falling out of competition when he covered the nine forwards in 36, the world number three needed three attempts to hack the green from the rough rough in the third, before drilling from 23 feet to save a double bogey.
But after firing a shot on the 10th, McIlroy picked up shots on the 12th, 14th and 17th to stand firm in pursuit of his fifth major title and the first since the 2014 U.S. PGA.
Scheffler overtook the two after seven holes, but then made birds in the eighth and 13th, threw from 55 yards for the eagle at par-five 14 and caught another shot on the 16th in his bet for a stunning fifth victory in 2022.
“I was very patient,” Scheffler said. “I was hitting pretty much most of the day. Two silly bogeys at the start of the round, but outside of that I got it right.
“If they had dropped a few more putts against (running) around the edge, it would have been a very special day. But three below was a good score for me, especially being two to six.”
Speaking of his eagle on the 14th, Scheffler added: “I did a great run through the middle and then I had a kind of funny lie where I was sitting on a downhill slope and it made the green shot much harder.
“I grabbed him with a thin hair and hit the tree. Luckily he didn’t hit the tree and he went back, he just fell in front of him. I lied well and hit a good chip and he came in.”
Fitzpatrick bounced back from a bogeys hat-trick to play his last five holes in two below par, as he sought to secure a Brookline double after his U.S. amateur triumph here in 2013.
“I played really, really well,” said Fitzpatrick, who was fifth in the U.S. PGA last month. “Three of my four bogeys were three putts, so that kind of summary of the day.
“I felt like I hit the green tee of the ball very, very well. I think I did a chip shot all day, so that sums up how good I felt like I hit it. I’m sorry. that I left a couple out there, which is pretty weird to say at a US Open, but it’s positive for the weekend. “