Borren shot 66 and 75 to finish the 36 holes on 141, tied with Mat Tautari (Invercargill) and Sungwoo Han (Queenstown).
Borren had the lead at lunch after finishing on 4-under-par 66 in the morning round and looked like running away with the title in the afternoon. He set up his leading score playing the homeward nine holes in 5-under-par in the morning.
He hit an iron closest to the pin on the 15th only to three-putt and followed it with a double-bogey six on the following hole to lose the lead.
He parred the final two holes and was forced to win the playoff to take the title.
Liz McRae (Wanaka) continued her monopoly of the women's event, scoring two rounds of 76 on Wednesday.
But this year's win was a family affair as her sister, Mary Hore, came second, six shots back.
Otago male triallists will be in Oamaru next weekend for the North Otago matchplay.