He’s 17 going on four-under 67

The best high school golfer in Southern California in the opening month of the season has been 17-year-old junior Nick Thomas of West Hills Chaminade.

He was the medalist in six matches, including a four-under 67 he shot at Sterling Hills Golf Club in Camarillo; won a tournament at Saticoy Country Club in Somis that included 96 players; and tied for first in another tournament at North Ranch Country Club in Westlake Village with 102 players.

Yet, despite placing first in almost every high school match he entered and appearing to be the master of his universe, he five putted at Torrey Pines Golf Course for a double bogey during a qualifying tournament, offering a timely lesson in humility.

It is these highs and lows that test golfers of all ages and types, and how they react and respond can separate the average player from the truly good ones.

“I tried to make sure it happened in the past,” Thomas said. “Just make sure I did well on the next hole. Stay in the present and focus. That’s where mental toughness comes into play. You’ve got to really be committed to playing all 18 holes.”

On the next hole, Thomas got a birdie, proving he had a short memory and could move on when one shot or a series of shots turned bad.

“He has a mental map of what he’s going to do and sticks to his game plan,” Coach Bryan Cantwell said. “He’s a golfer and not a hitter. He’s a finisher.”

A year ago, Thomas started to gain traction as one of the most promising golfers in Southern California. In June, he tied for sixth at the state championships at Poppy Hills Golf Club in Pebble Beach with two-over 74.

In August, he finished sixth at the California State Junior Amateur Championships at Oak Valley Golf Club in Beaumont, shooting five-under in the final two rounds.

On Monday, at the 54-hole L.A. city junior championships at Wilson Golf Course, he tied for third after rounds of 71, 69 and 69.

He has grown nearly 3 inches to reach 5-11, has a 4.1 grade-point average and seems convinced that he can succeed in a sport where perfection is rarely achieved.

“I’ve learned a lot about the game over the past 10 years,” he said. “It’s fun to be able to see myself improve and progress and see how far I’ve come.”

His father bought him plastic clubs when he was 3. He was hitting balls on the driving range at 6 and competing in tournaments at 8.

“Practice, practice and practice” is his motto.

“Because I make my practice simulate my actual play . . . then it’s not such a foreign place for me when I’m in a pressure situation because I know I’ve done it before,” he said.

There was a time he wasn’t thrilled with pressure. Not anymore.

“I can honestly tell you I like pressure,” he said. “It’s fun.”

His short game is solid and he can send a ball flying 275 yards down the middle of a fairway with his driver. He once played basketball and baseball, but golf keeps challenging him. Yes, the ups and downs can be frustrating, but Thomas is almost a psychologist in training.

“You’ve got to really instill that right mentality in you and make it a habit of your thinking,” he said, “and if you do then all of a sudden, it’s a lot easier to be in the tough situations.”