The judge dismissed Mr Bambury's claims on 26 works of art, while other disputed pieces could be the subject of further litigation.
The dispute was heard in the High Court at Auckland in May and high-profile names of the art world were dragged into the witness box.
Among them was Patricia Clark, who has represented some of the country's leading artists, including Mr Bambury and Billy Apple.
Speaking to NZME News Service after the judgment was delivered, both Mr Bambury and Mr Jensen claimed the spoils of victory.
Mr Bambury noted the payment he was due to receive.
"I feel relieved, after five years of persevering, to have got Jensen into court and to have the judge's verdict," Mr Bambury.
"I can now move forward feeling that I have achieved justice, having won 90 per cent of the law and being awarded some large financial results."
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The artist disagreed with Mr Jensen's assertion that "the vast majority" of Mr Bambury's claims had failed.
"If you want to look at this terms of wins and losses, he's lost.
"This is case law that is going to have some impact beneficially on the art world in New Zealand in general, beyond my own case."
But Mr Jensen said the judgment was not final and some details had to be amended.
For example, he said costs were still to be decided.
"It's one day after what has been a long and absurd and lamentable process," he said, speaking from his gallery in Sydney.
"Eighty-five per cent of the claims he made failed in the judgment."
The gallery director, who also has a business in Auckland, said he would discuss aspects of the judgment with his lawyer.
Mr Jensen said many artists supported him over the last few years and the court battle was often intensely "personal".
A reconciliation was unrealistic but he wished Mr Bambury "the very best of luck" for the rest of his career and life.
Justice Fogarty said both men were "strong personalities".
"By that I mean they had strong views and saw themselves, with some justification, as leading figures in the art world.
"Together they broke boundaries, exhibiting in Europe. Their relationship was very successful financially, for both of them."
New Zealand Herald art writer T.J McNamara previously described Mr Bambury's work as "rather severe, minimal abstraction" and said the artist was a mainstay of New Zealand art books.
- Additional reporting Jimmy Ellingham