The Magpies enjoyed absolute dominance at scrum-time and, in the 37th minute, scored their third try after a South Canterbury feed five metres from the tryline.
Pressure from the Hawke's Bay pack saw the ball spill out the side of the scrum for an easy try to halfback Connor McLeod.
Magpies halfback Connor McLeod scores in the first half. Photo / Paul Taylor
A brilliant counterattack after the halftime siren from debutant winger Paoraian Manuel-Harman allowed fullback Caleb Makene to score the Magpies' fourth.
Both teams came close to scoring in the opening 10 minutes of the second half with Hawke's Bay held up over the tryline and South Canterbury forced out just short by some desperate cover defence.
McLeod got his second try in the 57th minute from a nice inside ball by first five eighths Lincoln McClutchie.
That was the halfback's last act of the game with debutant Sheridan Rangihuna coming on to replace him.
McClutchie set up the next try as well, breaking the line and teeing up Manuel-Harman to score in the 64th minute.
Tighthead prop Lewis Bush and second five-eighths Zack Simpson both got off the bench for their Hawke's Bay debuts before fulltime.
South Canterbury finally scored a well-deserved second try in the 72nd minute through second five Paula Fifita.
It looked like the hosts might have had the last say but Rangihuna was held up over the tryline in the 79th minute.
Instead it was South Canterbury who scored another sublime try after the final hooter, with Theo Davidson scoring in the corner.
The next Ranfurly Shield defence is against Poverty Bay on July 30, a week before Hawke's Bay get their Bunnings NPC season underway against Waikato in Hamilton.
