The Mahora School Year 5 pupil relished the chance to compete with the world's elite young golfers.
"It was awesome," he said.
The level of professionalism was an eye-opener for Tuhourangi and his father Manuel.
"It's amazing the lengths they go to over there," Manuel said.
"Nine and 10-year-olds with psychologists, dieticians and live-in coaches. We don't want that for him just yet."
The sweltering San Diego sun took its toll on Tuhourangi's game.
Despite playing in 35C heat with 80 per cent humidity, he managed to finish midfield.
"I did alright," he said.
While the trip was strictly business, Tuhourangi did get the chance to visit the local zoo.
Surrounded by lions, tigers and bears, Tuhourangi only wanted a photo of the resident donkey.
While most golfers can struggle to keep their emotions in check, Tuhourangi plays each stroke with a clear head. "Just forget about the last shot," he tells himself.
Golf is a tough discipline to get kids to commit to.
Manuel said Tuhourangi's brother "would be chasing leaves by the third hole". Tuhourangi's favourite golfer is Northern Irishman Rory McIlroy "because he's No1".
His favourite course is at his local Karamu club, where he nearly shot his first hole-in-one after lipping the hole on six.
His best round at the course is an impressive 77.
Playing off a 15 handicap, Tuhourangi is relishing his first year in the Hawke's Bay Golf Academy of 26 talented amateurs.
Here he plays with like-minded individuals who feed off each other in a stimulating environment.
"It helps him with his mental side of the game, course management," Manuel said.
And although he can drive 160m, he said his short game was his strength, thanks to countless hours of practice.
"He started watching golf on TV with me and from age 4 he was swinging a club," Manuel said.
On Sunday Tuhourangi will take part in the Hawke's Bay junior intercity competition at Maraenui Golf Club.
A far cry from the greens of California, it will just be another round on his journey to achieving his dream of becoming a professional golfer.