Herman and Kirk closed with 2-under 70s on Sunday to finish at 11-under 277 at Moonah Links. Herman earned $126,000 in the event also sanctioned by Australasian tour.
The 32-year-old Herman, a former University of Cincinnati player who spent two years as an assistant pro at Trump National in New Jersey, opened with a course-record 62 on Thursday and led or held a share of the lead after each round.
Kirk birdied Nos. 14 and 15 to take the lead at 13 under, but dropped strokes on 16 and 17 and missed a 4-foot birdie try on 18.
In the playoff on the par-5 18th, Herman hit his approach to about 5 feet to set up his winning birdie putt. Kirk was in trouble off the tee, hitting into the left rough.
"I'd like to thank my friends and family who have stuck with me through some difficult times," Herman said at the trophy presentation.
American Robert Gates, the New Zealand Open winner last week in his Nationwide debut, shot a 66 to finish third at 10 under.
"I played great down the stretch," Gates said. "It's fun. It's been a great two weeks, and I've played very well."