You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
He and seven other viticulturalists competed in the selection competition at Otago Polytechnic's Central Campus Bannockburn last Thursday and then during the awards evening at the Bannockburn Hotel.
Ben Holt from Akarua Winery was second and Katrina Jackson from Chard Farm was third.
Mr Gourley said he did not expect to win.
"I was very happy to take it out," Mr Gourley said.
"There were lots of congratulations and a lot of people were very happy."
At 28 he had entered the competition before, winning the Central Otago Young Viticulturist 2013 competition and Cellar Hand of the Year 2016 event (now Winemaker of the Year).
Regional organiser Nick Paulin said Mr Gourley and seven other contestants aged from 22 to 28 took part in several modules, including spraying, trellising, pest and diseases, irrigation, budgeting, a blind wine tasting and an interview at the evening session.
"The pests and diseases was the most in-depth section, with bits of it easy and bits definitely challenging," Mr Gourley said.
He completed a bachelor's degree in viticulture and oenology at Lincoln University and has worked for Two Paddocks, and then the Central Otago Wine Company.
He has also worked in Australia and France and was part of a group that looked at establishing a wine industry in Papua New Guinea.
In preparation for the national competition, he has been offered help from within the wine community, and is to receive his project brief (part of the national competition) on Monday.
"I'll also look at my results from yesterday and see what areas I need to focus on and I'll talk to previous winners and get some knowledge from them."
Domaine-Thomson operations manager Kate Barnett was delighted with Mr Gourley's success.
"It was awesome," she said.
"The whole Domaine-Thomson team is so proud of Simon.
"He has been with us for over a year now and does such a great job."
Mr Gourley will compete against representatives from the other wine regions and the winner of that goes on to represent the wine industry in the Young Horticulturist of the Year Competition in November.