"Conditions were really bad with torrential rain and gale-force winds but I just kept my head down and played on and in the end the course played pretty well," he said.
Yesterday brought near-perfect conditions and McKeown's Northland teammate Sean Masters made the most of them to fire the best round of the weekend with a 68.
After an exhausting recent schedule of golf, McKeown now has a week off before the Tauranga Open next weekend.
A good result there is likely to convince the Northland selectors that he is ready to play interprovincial golf if the classic win hasn't already.
Omaha's Mike Leeper finished in a tie for second with a final round of 71, with Royal Auckland's Fraser Wilkin, but Leeper finished as the runner-up after a countback.
Titirangi's Brittany Dryland was the winner in the women's competition with rounds of 86, 84 and 78 for a total of 248, well ahead of Kylie Jacoby with 256.