The drama ensured the small but vocal crowd got behind the New Zealand team early on, while Gemmell admitted his side was caught off guard by the Australians' challenge.
"We hadn't even discussed that, them advancing or any of that sort of carry-on, and all that did was fire them up some more and it probably put us off our game to start with.
The boys got a little bit excited at the start and our tackle technique was out the window. The game settled down and we got our fair share of possession and converted that into field position which eventually got us points."
The drama continued throughout the match, with several altercations taking place, and beyond the fulltime siren, when Junior Kiwis prop Sam Lisone was penalised for a shoulder charge that forced Australian halfback Ryan Matterson from the field.
The Kiwis' celebrations were cut short when the Junior Kangaroos were awarded a shot at goal from 40 metres out but fullback and Manly first grade regular Clint Gutherson's attempt sailed wide.
Gemmell questioned the validity of the penalty and defended Lisone's charge-down attempt as Matterson took a last-ditch shot at a field goal.
"I don't think there was any malice in it, I don't think it was a penalty to be fair, but what's done is done and fortunately it missed."
Earlier, both sides were unsuccessful in trying to break a 14-14 deadlock before Junior Kiwis and Wests Tigers five-eighth Te Maire Martin slotted a 79th minute field goal for the match-winning lead.
"We thought they might have been a bit more urgent about taking it but we got the job done," Gemmell said.
