Updated

PEBBLE BEACH, Calif. (AP) — Morgan Hoffmann raised his arms in celebration after the putt dropped, fished his ball out of the cup, pivoted and chucked it into the Pacific Ocean with a grin on his face.

The perfect reaction to making a quadruple-bogey nine.

"I felt like Tin Cup, honestly," Hoffmann said.

The 20-year-old Hoffmann, who just completed his sophomore season at Oklahoma State, found himself loitering near the top of the U.S. Open leaderboard in Thursday's first round. He shot an impressive 34 on the front-nine and found himself at 2-under after making a birdie on the 15th.

After a par at the 16th, Hoffmann's round quickly devolved. He bogeyed the difficult 17th after a poor chip shot and that was followed by his adventures on the closing hole.

"Eighteen is my favorite hole on the golf course," Hoffmann said. "I was looking forward to it all day."

His tee shot found the fairway, but carried too far and Hoffmann found himself blocked from advancing by a tree. His options: play to the right, requiring a hook of nearly 50 yards to bring the ball back to the fairway, or try a low cut underneath the tree limbs.

He tried the second option. A bulky tree limb got in the way, sending his ball ricocheting into Stillwater Cove. After dropping, Hoffmann came over the top of a 7-iron, hooking another into the inviting waters of the Pacific.

Hitting his sixth, Hoffmann found a greenside bunker. His seventh was left in the bunker and he blasted out with his eighth. Finally, Hoffmann ended his adventure by dropping a 10-foot putt to avoid double figures.

"It just felt good to finally get it in the hole," Hoffmann said. "After nine shots it's nice to see the ball go in."

The rest of his group felt for the youngster, who played on the United States squad in the 2009 Walker Cup.

"Unfortunately it happens on the last hole," Rikard Karlberg said. "But he will come back. He played really solid, really good."

Hoffmann's resume says he could be another young star in the making. He was an all-American as a freshman at Oklahoma State and reached the quarterfinals of the U.S. Amateur in 2008 as a 19-year-old.

He played confidently for 17 holes and said the breakdown on 18 won't linger into his second round.

"I had a great day. It just sucked to end on that," Hoffmann said. "I'm playing really well and going to go out there tomorrow and keep my head high."