Royal Liverpool's brand new par-three hole, featuring an upturned saucer green guarded by deep bunkers, has been predicted to cause problems.
But Smyth took the hazards out of play with a superb tee shot struck with a nine-iron, the ball taking a hop before disappearing as huge roars rang out across the course.
The Open debutant had double-bogeyed the same hole on Thursday but now goes down in the history books as the first player to ace the new hole.
"It was amazing. Bittersweet actually," said the pony-tailed Smyth.
"I had a shock the day before, made double bogey, and I was just really happy I hit a good shot because I was just so disappointed from the day before.
"It was a moment I'll never forget. It's crazy."
Sadly for Smyth, it only improved his overall score to eight over and he will miss the cut for the weekend, although he was congratulated by compatriot and reigning champion Cameron Smith.
"Pretty cool. I don't know Cam too well, but just enough to have chit-chat here and there, so that was cool," he said.
Smyth was one of the players that joined the Saudi-backed LIV Golf last year, raking in $1 million from three events.
Asked if he would swap that for his hole-in-one, he said: "Ooh, that's a tough one. Probably a million dollars."
