Shawn Stefani lost track of the ball as soon it rocketed off his 4-iron.
A roaring U.S. Open gallery tracked it for him.
"Go! Go! Go! Go!"
It did Sunday when Stefani aced the 17th hole, making him the first golfer to make a hole-in-one at any U.S. Open at Merion Golf Club, which is hosting the major for the fifth time.
"When the crowd went crazy, I knew it went in," he said.
His shot bounced out of the rough and rolled some 50 feet toward the pin before falling in the cup.
Stefani raised his arms and hopped around the tee in celebration. Caddie Chris Callas gave him a playful hug and a slap on the back.
"I didn't know what to do but jump up and down for joy," Stefani said.
Then he walked down the 229-yard, par-3 hole and planted a kiss on the sweet spot where it landed.
"We're in Philly. There's some great fans up here and I know they can be tough on you and they can love you forever," he said.
USGA Museum officials waited for Stefani near the scorecard trailer and hoped to acquire the ball. Stefani declined.
"It's hiding right now," he said. "I'm going to save it."
But he did pull the ball out of his pocket and showed it off. He also inquired about getting some sort of commemorative plaque from Merion.
The USGA's Far Hills, N.J. museum didn't go home empty-handed -- Stefani donated a signed glove and scorecard.
His only other ace came when he was 13 at Goose Creek Country Club in Baytown, Texas, his hometown.
It was the first ace at Merion, but not at a Philadelphia Open. The first U.S. Open hole-in-one came in 1907, when Jack Hobens aced the 147-yard 10th hole at the Philadelphia Cricket Club.