Australian teenager Keeley Marx has won the IMG Academy World Championship in San Diego.

Marx made a closing bogey at Torrey Pines North Course in the final round but her three-under par 69 and 10-under overall for 72 holes was enough for a tense one-shot win over American Raya Nakao in the 15-18-year-old girls’ division.

Another American, Sammie Miller, was tied with 18-year-old Melburnian Marx going up the last hole, but made a triple bogey seven.

Australia also won both the teams events, with Jye Halls and Kai Komulainen on top in the boys championship, and Marx joined by Brielle Mapanao to win the girls' title.

“I am ecstatic,” said Marx, who was co-captain of the winning Victorian team at the Golf Australia Interstate Series in Sorrento earlier this year. “It’s such a good feeling to come over here representing my country playing at an international level. It’s such a cool experience.

“I’m still over the moon. I don’t even know what to think now. I can’t wait to celebrate with the team tonight.”

Marx admitted to some nerves going down the stretch. “I was just trying to breathe and get my heart rate as low as possible. I was quite nervous going down the last,” she said.

Her tee shot at the 72nd hole fanned to the right, but she scrapped a bogey that proved to be decisive. “The emotions were high but I ‘m glad I was able to calm them down at the end and get it done.”

The teenager plays out of The Heritage in Melbourne and has been a regular state team member.

New South Wales star Jye Halls closed strongly with a 68 to finish runner-up in the boys’ 15-18 division.

Results