The Wellington baritone will fly to London to audition for three opera schools there.
Now 25, he has been singing since the age of 17 but said he only became serious about it four years ago, when he began lessons with Margaret Medlyn and Bruce Greenfield.
"This is the competition where people like Jonathan Lemalu and Anna Leese started. I want to do what they have done," he said.
O'Connor completed a bachelor of music degree in performance voice at Victoria University in 2007.
He now works on a construction site, with strict instructions not to sing on the job.
"They say it echoes around the building too much."
The ODT aria competition is the highlight of the Dunedin Competitions Society senior vocal competitions, which began on Thursday.
One thing the audience knew at the final last night was that this year's winner would be a man, as for the first time organisers could remember, no women made the cut.
Judge Adele Johnston, of Sydney, selected five finalists, but that became four after Auckland tenor Darren Pene Pati developed voice problems and withdrew.
Ms Johnston described O'Connor as an intelligent and musical singer whose voice she was certain would develop well, awarding him the the Celebration of the Century Cup and $5000.
Last year's runner up, Dunedin baritone Julien Van Mellaerts, was runner up again, winning $3000 and the Chambers Family Trophy, while bass-baritone Tavis Gravatt, of Auckland, was placed third and won the Honor McKellar Award and $1000.
The other finalist was Dunedin tenor Michael Gray, now studying in Wellington.
