The Kaiapoi golfer's outstanding performance was the catalyst to lead the New Zealand team to a tie for fifth in the Eisenhower Trophy, a huge step up from their 35th place last year.
For Kobori, he is just the second New Zealander to win the individual title, following Phil Tataurangi in 1992.
After three rounds of 70,70,67 he trailed the three players tied for the lead by two shots going into the final round, and nothing less than a brilliant final round 65 was required to give him a one-shot win.
He battled illness all week so his final round was all the more outstanding.
Birdies on one, four and six set him up nicely for another on 10.
A bogey on 11 was a brief hiccup followed by birdies on 12, 13 and 17.
His closest rival, US Amateur champion Nick Dunlap (United States), was also scoring well and was tied with Kobori after 17.
However, on the final hole, a par 5, Kobori sensationally chipped in for a winning birdie.
Finishing 16 under par he said: “I played nicely. I think I made 16 birdies which is always fun.”
The New Zealand team is in Melbourne for the Asia Pacific Amateur Championship this week so there is another string Kobori will look to add to his bow.
“The team should be proud of its fifth finish this week," Kobori said.
Kobori's teammate, Taranaki golfer Sam Jones, shot the second counting score on Sunday, a one-under 71, contributing to the team score for a third time, while Jayden Ford shot even in his final round.
By Neville Idour
