Correction: A previous version of this article incorrectly said that Beau Hossler was the only amateur to make the cut. Amateurs Jordan Spieth, Patrick Cantlay and Hunter Hamrick also made the cut.

Whatever happens to Beau Hossler over the rest of his life — and at 17, he has plenty left to live — he will always have that moment Friday afternoon. The rising senior at Santa Margarita High, south of Los Angeles, birdied the difficult first hole at the Olympic Club to get to 2 under par. He led the U.S. Open by himself.

“I was pretty excited about it, but then again, I had another 40 holes, at least, to be playing in the tournament,” Hossler said. “You got a long way to go and you can’t get too wrapped up on where you’re at.”

Predictably, Hossler’s moment slipped away quickly. He bogeyed the second hole — his 11th of the day — to drop back into a tie, and a wayward tee shot at the fourth led to a double bogey. Still, Hossler acquitted himself more than admirably. He chipped in for birdie at the seventh and shot 73 to stand at 3 over and easily make the cut.

“I felt I was getting into a little bit of a zone,” Hossler said. “Unfortunately I kind of lost it coming in.”

Two paths, same exit

Casey Martin’s locker at the Olympic Club was in the same corner as Rory McIlroy’s, and when Martin finished his second-round 75, he headed back to collect his belongings. The University of Oregon golf coach — known in his sport for suing the PGA Tour for the right to compete with a golf cart because of a lifelong circulatory problem in his right leg — introduced himself to the 2011 U.S. Open champion.

“Sorry you didn’t play your best,” Martin said, shaking McIlroy’s hand, and McIlroy thanked him.

No two competitors arrived here with more disparate expectations. Martin, who hasn’t competed in six years, went through local and sectional qualifying to return to Olympic, where he made his only previous U.S. Open appearance in 1998. But he finished 9 over par and, like McIlroy, missed the cut.

“Just missed a lot of putts and hit a few loose shots when it was important,” Martin said. “But it’s wonderful competing. I haven’t done it in so long, it really feels great to get out there and grind away.” . . .

First-round leader Michael Thompson backed up his opening 66 with a 75, including double bogeys at 12 and 18, holes he birdied Thursday — to drop to 1 over.

“Yesterday was an unbelievable round and didn’t by any means expect to go out and do the same thing,” Thompson said. “Just go out and survive, and I felt like I did that.” . . .

Fairfax native Steve Marino, who had played two competitive rounds in the past four months because of a knee injury, shot a 78 Friday to finish at 22 over, tied for 153rd in the 156-man field.