Release courtesy of USGA/David Shefter

Martin Kaymer, who won the 2010 PGA Championship and last month’s Players Championship, carded a 5-under-par 65, the lowest round ever shot in a U.S. Open contested at Pinehurst No. 2. Kaymer registered six birdies – four on the inward nine – against one bogey on a course that measured 7,360 yards for the first round.

Kaymer finished the day three clear of McDowell, Kevin Na, Brendon de Jonge and Fran Quinn, a 49-year-old sectional qualifier from Holden, Mass., who is playing his first U.S. Open in 18 years. The group at 1-under 69 includes world No. 2 Henrik Stenson, Jordan Spieth, Matt Kuchar, Dustin Johnson, Keegan Bradley and Brandt Snedeker.

Six-time runner-up Phil Mickelson, needing a U.S. Open title to complete the career Grand Slam, shot an even-par 70, while defending champion Justin Rose carded a 72.

Only Snedeker, who posted a 4-under 31 on the outward nine, matched Kaymer’s birdie output.

Fifteen players finished under par and the scoring average was 73.23, the lowest since the 2003 U.S. Open at Olympia Fields.

Kaymer’s 13-under effort at The Players at challenging TPC Sawgrass provided much-needed momentum and confidence coming into the year’s second major championship. Before that title, he had not finished better than a tie for 18th since Jan. 1 and had not won since the 2012 Nedbank Golf Challenge in South Africa.

“I needed a win,” said Kaymer. “I needed it for my confidence and all the work I’ve put in.

“I hit the ball very solid today. I didn’t make very many mistakes and I made a few putts in the end.”

Kaymer quietly made the turn at 1-under 34 before making a 4 at the par-5 10th. Then he closed with three birdies in a four-hole stretch – starting at No. 14 – to break away from the pack.ber

“Well, I got asked yesterday what score I would take for the whole week and I said 8 over par, so hopefully that’s not going to happen,” said Kaymer. “I thought [the course] played a little more difficult on Monday, Tuesday and Wednesday. They must have put a little more water on the greens last night. I thought it was very playable.”

Entering the championship, some believed a layout devoid of thick, gnarly rough, a characteristic synonymous with U.S. Opens, would make it easier for the world’s best golfers. When architects Bill Coore and Ben Crenshaw restored Course No. 2 to Ross’ true intentions, the Bermudagrass rough was replaced by native areas featuring wiregrass, sand and pine straw.

Early reports from the players suggest the restoration has been well-received.

“It’s a little different, yes,” said Na. “You know you’re at the [U.S.] Open, but you see no rough. It’s hard to get used to. I think it makes the golf course a lot more fun. It tests all kinds of shots in the bag and I think that’s great.”

Added Bradley: “They’ve done an unbelievable job. It’s the best setup I think I’ve ever played. If you hit the ball in the fairway, you can attack and you can make birdies right now. But if you hit the ball in that waste, even if you’ve got a good lie, it’s hard to hit a good shot.”

Since his victory at Pebble Beach (Calif.) Golf Links in 2010, McDowell has enjoyed more success at the U.S. Open than any other major. He fell one stroke short of tying Webb Simpson in 2012 at The Olympic Club and tied for 14th in 2011 at Congressional when fellow Northern Irishman Rory McIlroy shot a championship-record 16-under 268. McDowell has repeatedly said the U.S. Open is the major that likely suits his game best because of the premium put on accuracy.

An eagle-3 at No. 5 on Thursday highlighted what was a routine opening round: 15 pars, one birdie, an eagle and a bogey.

“I positioned the ball great off the tee,” said McDowell, whose last win in the U.S. came at the 2013 RBC Heritage. “But generally I kept the ball exactly where I wanted to going into the flags. I was on the correct side of most of the flags. I [lag] putted well and holed out extremely well, which I’ve got to keep doing this weekend.”

Na was one of the last exempt players into the field, moving from outside the top 60 of the Official World Golf Ranking to No. 40 following his runner-up finish at the Memorial two weeks ago. He maintained his No. 40 ranking through June 2 to become exempt to the championship on Monday. Like McDowell, Na eagled the par-5 fifth, although he holed a chip shot for the 3. He also had three birdies against three bogeys.

“It was a lot of fun,” said Na, who had never bettered par in his previous eight U.S. Open rounds. “I hit it great today. I think I missed one fairway. Obviously, my ball-striking was there.”

De Jonge, of Zimbabwe, is playing in his second U.S. Open and first since 2010 when he opened with a 69 at Pebble Beach and finished tied for 33rd. Exempt due to making the Tour Championship last fall, the Virginia Tech graduate is still seeking his first PGA Tour victory. But other than a tie for sixth at the Wells Fargo Championship in his adopted hometown of Charlotte, N.C., the 33-year-old has struggled to get inside the top 15 this season.

Perhaps his opening round at Pinehurst, in which he shared the lead in both driving accuracy and greens in regulation, will be a harbinger of things to come.

“I feel like it fits my eye a lot off the tee,” said de Jonge, who played the North & South Amateur at Pinehurst during his collegiate days. “I feel like a lot of the holes shape how I like to see the ball going a little bit left to right.”