“But I haven’t finished top 10 in majors or anything. Haven’t really been in the majors. I want to play better in the majors. I feel good.”

Italy’s Francesco Molinari, the 2018 British Open champion, and Spain’s Rafa Cabrera Bello, a back-nine starter who holed out from just inside 60 feet to eagle the 18th, shared second on 68.

Four-time major winner Brooks Koepka was in the clubhouse sharing fourth on 69 with local favourite and world No 6 Xander Schauffele.

World No 63 Henley opened with a bogey after finding a greenside bunker, but answered with a nine-foot birdie putt at the fifth, an eight-footer at the seventh and another birdie from just outside 14 feet at the par-3 eighth.

Henley began the back nine with a birdie on a 12-foot putt and answered a bogey at 12 with a three-footer to birdie 15 and his key closing putt.

“You just have to pick a shot and commit to it,” Henley said. “For me, I think it’s just being comfortable.

“I putted nice. It was a good way to finish off a good day. It’s just a tough test. You’ve got to hang around.”

A day after his 51st birthday, hometown hero Mickelson stumbled to a 75 with three bogeys in his first six holes. He recovered with a 10-foot birdie putt at the 17th but bogeys at six and seven saw him into the clubhouse eight off the pace.

“Fought hard, made a lot of short putts to kind of keep myself in it and then I ended up bogeying six and seven,” Mickelson said. “I’m a little disappointed about that.

“I feel like I’m close to putting together a good round.”

But the US Open has eluded the 30th-ranked left-hander, who has settled for a record six runner-up showings.

Mickelson hopes to join career grand slam winners Tiger Woods, Jack Nicklaus, Ben Hogan, Gary Player and Gene Sarazen.

World No 10 Koepka, who underwent right knee surgery three months ago, seeks his third US Open win in five seasons.

Koepka rolled in a 20-foot birdie putt at the 12th, holed a 42-foot bomb at the 17th and closed his first nine with a tap-in birdie at 18.

Koepka seized the lead with a nine-foot birdie putt at the par-5 second but bogeys at the par-3 third and par-4 seventh dropped him back.

“The wind picked up,” Koepka said. “It made it quite difficult. It made it quite interesting for sure.”

Early morning fog rolled in off the Pacific Ocean to delay the start by 90 minutes as a field of 156, with Mickelson the eldest, tested the formidable 7,652-yard layout.

Such late-starting stars as fifth-ranked defending champion Bryson DeChambeau, four-time major winner Rory McIlroy, world No 1 Dustin Johnson and third-ranked Jon Rahm could be racing the darkness to complete their rounds.

Johnson, last year’s Masters champion, could be overtaken in the rankings if No 2 Justin Thomas or Spaniard Rahm win the US Open.

To be dethroned, Johnson would need to finish worse than solo 17th if Thomas won or worse than a two-way share of 18th if Rahm won.