The 23-year-old said what won it for him was simply keeping the ball in play and giving himself chances to birdie.
Edwards said he did not have a set game plan going into the final round and just tried to keep playing well.
"I just wanted to give myself some opportunities to make some birdies, and the irons went well and so did the driver."
He said he had hit a drive out of bounds on the 18th hole before and aimed well left yesterday.
"That's why my drive went way left."
He still parred the last and came away with the title.
Edwards, who works as a greenkeeper at Lake View Golf and Country Club, carded rounds of 65, 68, 68 and 66.
He has won the tournament once before in 2010 and has also won two titles at the Springfield Open (2012 and 2014).
Meanwhile, second-placed Beard finished with rounds of 71, 68, 67 and 65.
Rotorua's William Howard also had a good tournament finishing in third place with rounds of 69, 66, 70 and 73 to finish two-under par.
More than 100 golfers competed in the Open which started on Friday and ran for three days.
The tournament has long been an amateur event but partnered with the New Zealand PGA Trainee Championship this year, giving it Pro-Am status.
A total of 36 trainee professionals undergoing a three-year professional apprenticeship with the New Zealand PGA competed for prize money.
The trainee professionals finished down the leaderboard with the top pro, Ben Guilford, finishing eighth overall at two-over par.
Guilford is a former Rotorua Golf Club member.
