The Monaghan pair finished just over a minute clear of nearest rivals Frank Wray and Kieran McGrath in another Impreza.
Aaron MacHale/Paul McGee took third place overall, beating Shane Maguire, the son of the outright winner, and Stephen Thornton to top place in the Group N Production class.
Dubliner Peter Grimes, already the Northern Ireland Autotest champion six times, got his title defence off to a good start with a narrow win in the opening round at Craigavon. At half distance, he lay third, ten seconds behind leader Ashley Lamont, but the Antrim driver lost time with a mistake and a pylon penalty and Grimes came through to win by 1.4 seconds.
