Bryson DeChambeau's confidence is at an "all-time high" after an excellent two-under 68 put him in contention following his second round at the U.S. Open.

Players and experts alike commented about how forgiving the notoriously brutal Winged Foot West Course was on day one, but the same could not be said on Friday.

The number of players finishing the day under par fell drastically, with Thomas Pieters and Matthew Wolff – both of whom were just a shot off the lead after the opening round – among those to slip, with each going four over par this time around to drop back to level.

But long-hitting DeChambeau, who carded 69 on Thursday, put himself right into the mixer with an impressive round for the clubhouse lead.

"I feel great. Confidence is at an all-time high right now," he told reporters. "I'm driving it well, iron play is fantastic, wedging is getting better each and every day, and I'm putting it like I know I can. So very happy.

"I want it to play as hard as possible. I feel like there's so many holes out here that I can take advantage of that some people can't.

"Now, that doesn't mean that I'm going to win or anything, you've still got to execute, you've still got to hit the driver straight.

"If I'm hitting the driver far but all over the place, you can't make birdies from the rough. It's very difficult to, so I still have to work on hitting it straight while hitting it far. And that's a unique combo that I'm going to strive for for the rest of my life."

With regards to his improvement, DeChambeau put it partly down to his approach play with the wedges, with calibration adjustments paying off.

"My wedges yesterday weren't that good," he said. "I was flying them too far and I wanted to know what the problem was and we figured out what the problem was.

"It just was going farther than I thought it was. We didn't practise them as well as I should have leading up to this tournament, but we made that adjustment, and it worked out beautifully for me today."

World number one Dustin Johnson appeared to be in trouble after his opening-round 73, but on Friday he went around at even par to remain on three over for the tournament, and given how aggressive the course felt on Friday, the 2016 champion believes his chances are still alive.

"I think still on this golf course, with the conditions that we're supposed to have the next couple days, I don't feel like I'm out of it," Johnson said. "I'm going to have to play really well, but I like where I'm at. I think obviously two solid rounds and [I'm] right back in the mix.

"So hopefully. It was a little better today, get a little better tomorrow and then even better on Sunday, and I'll be right there."