RORY McIlroy is just one shot off US Open leader Collin Morikawa as he chases a long-awaited fifth Major at Brookline.
The Northern Irishman has overcome a disappointing start to put himself in the hunt for his first Major success since 2014.
He trails joint leaders Morikawa and Joel Dahmen, with the American pair both on five-under-par.
But it is a competitive field heading into the weekend action, with McIlroy one of five golfers on four-under-par.
He is joined by reigning Spanish champion Jon Rahm and the American trio of Hayden Buckley, Aaron Wise and Beau Hossler.
Current Masters Champion and world no.1 Scottie Scheffler is just one shot behind that group, while Matt Fitzpatrick is the leading Englishman on two under.
McIlroy said he "couldn't be happier" as he looks to chase down Morikawa and Dahmen in Massachusetts.
He said: "I think I ride waves of momentum pretty easily. Certainly whenever you get on the crest of a wave, you try to ride it as long as you can, and I’ve gotten a little bit better at trying not to ride the other ones downwardly.
"This golf course, there’s a nice flow to it that you can get on a little bit of a run and start to make some birdies, and if I do encounter that this week, I feel like I’m pretty good at riding those sort of waves of momentum through the course of a round.
"I think I play quite an emotive brand of golf, if there is such a thing.
Most read in Sport
JOIN SUN VEGAS: GET A FREE £10 BONUS WITH 100s OF GAMES TO PLAY AND NO DEPOSIT REQUIRED (Ts&Cs apply)
"I’ve always liked having crowds. I like the interaction. I enjoy that part. I like seeing people out there. Maybe that’s part of it.
"I’ve been out here a long time. Maybe they feel like they’ve watched me grow up and they’ve sort of been on that journey with me."
On his slow start, he added: "I stayed patient, and I knew I was going to give myself chances if I just hit the ball the way I’ve been hitting it.
"Today was a really good example of just having a good attitude. I’m really happy with my position. Came back well today after a tough start and right in the mix. Couldn’t be any happier."