Island golfer Tony Grillo shot a one-under par on Thursday at a qualifying event at Maplegate Country Club in Bellingham to take third place in the field and earn a spot in the U.S. Amateur Open, the leading annual golf tournament for amateur golfers that has been won by golfing legends like Tiger Woods, Phil Mickelson and Jack Nicklaus.

The event will be held from August 24 through August 30 at Southern Hills Country Club in Tulsa, Okla., the same course where Tiger Woods sank a long putt on the final hole to win the 2007 PGA championship. Both the winner and runner-up of this year’s Amateur Open will win an automatic bid to three of golf’s majors: the Masters, the U.S. Open and the British Open.

But Grillo, who at the age of 19 is already among the nation’s best young golfers, said he is focused on getting past the first cut; the tournament begins with 36 holes of stroke play for two days before the field of 312 is reduced to 64 players for match play the rest of the way.

“I’m not thinking too much about winning. I’m really focused on getting past the first two days. I will be playing against the best amateurs in the world, so I’m trying to be realistic,” he said.

After graduating from the Martha’s Vineyard Regional High School last June, where he excelled on the varsity golf team for four years, Grillo enrolled at Harvard University and played on the school’s golf team. While he had a mediocre year on the team, he has seen marked improvements in his game this summer.

“Everything went great [at Harvard] but I sort of had a disappointing season. That’s why my play this summer has been so rewarding. I really turned things around,” he said.

In the 36-hole qualifier last Thursday at Maplegate, Grillo was paired with Matt Jager of Australia, ranked as the 95th best amateur golfer in the world by the R& A World Amateur Golf Ranking Web site. Grillo is not ranked on that site, although he may soon be, after besting Mr. Jager during a single-hole sudden death playoff.

Grillo shot a one-under 71 in the morning round, and kept pace with Jager for most of the second round. On the final hole of the day, he lined up for a long 20-foot birdie putt when his caddy, Gregg Leonard, a former teammate on the regional high school team, took him aside for a chat.

Although playing against Jager, he was ostensibly playing against the whole field in hopes of winning a berth in the U.S. Amateurs, and Leonard told him he probably needed to sink the birdie putt to finish the match under par and earn one of three spots open in the national tournament.

So like clockwork, Grillo lined up for the putt, took a few practice strokes and sank it, forcing a sudden death playoff. Although emotions were running high, Grillo made quick work of the playoff; making par on the first hole to Jager’s bogey.

Grillo said it was not his best game.

“To be honest I left a few strokes out there. I missed a few short putts, but I chipped in a few shots to even things out. Overall I am feeling good about my play heading into the amateurs,” he said.

He said he doesn’t know a lot about the course at Southern Hills, which was designed by legendary golfer Ben Crenshaw and features a long par five (653 yards) on the fifth and a short par three (173 yards) on the eleventh.

Over the next few weeks Grillo plans to sharpen his game by playing at his unofficial home course: Farm Neck Golf Club. And he said he is not nervous — at least not yet.

“Maybe it hasn’t set in yet. But I’m not that nervous; maybe when I get there that will change, but right now I am just really excited more than anything,” he said.