He turned five under par after just 10 putts on the first nine, including eight successive one putts.
There was a threatened meltdown with a double-bogey, bogey hit but Cusdin regathered to finish birdie, par, birdie, par to match Kennedy who had led for most of the day.
Cusdin has mixed work and golf this year with a win in the Tauranga Open. He plans to move to Melbourne next season to have a shot at a full playing programme.
Kennedy benefited from his early start, the lack of wind during his round and his course management.
Others like David Smail and Michael Campbell who were expected to give the field a shake, both made fateful mistakes on the fifth hole.
They triple bogeyed the par five and then, several groups behind them, Philip Tataurangi repeated the same blemish.
The last Kiwi to win the tournament in 2003, Mahal Pearce, also had trouble on the same hole but steadied to post a two under 70, a score matched by the seasoned Craig Parry.
Pearce mixed four birdies with two bogeys and attributed his success on the greens to the keen eyesight of his teenage caddy Thomas Facer.
"He can read putts like nothing else and I holed a lot of good six-footers for par, a few for birdie and most importantly on the fifth."
Pearce and his group had been told to lift their pace and Pearce promptly sent his three-wood into the water.
But he saved bogey with a strong putt, birdied the eighth and saved par on the last.
"I have always struggled to read greens for as long as I can remember. Thomas read everything perfect."
Kennedy began with birdies on his first two holes, settled for three more and a solitary bogey.
"It was getting breezy but I was fortunate to be out early," he said.
Kennedy, at 228, is the top-ranked player in the field, spends most of his year playing in Japan but is also familiar with the Clearwater layout.
"It was a bit tricky but the greens were fantastic and faster than they looked. You have to manage yourself around this course," he said.
Ryan Fox, Jake Higginbotham and Tim Leonard were leading the amateurs after they all opened with par rounds.