And here we were thinking it was all down to hard work, good underage structures, plucking from the Pacific islands and God-given ability.
The All Blacks had it put up to them last night.
The world champions first had to face an almighty Sipi Tau [war dance] in the midst of their own Haka.
Then, despite two first half tries, the Tongans battered them back onto their own tryline and were only saved from conceding a score because Irish referee John Lacey was too quick on the whistle.
They led 14-3 at the break but Tonga were on top.
Well, then, luckily someone brought the half-time bananas.
TIL: The @AllBlacks eat bananas at halftime just like us regular folk. #RWC2015 pic.twitter.com/qiNv8fsohs
— USA Sevens Rugby (@USASevensRugby) October 9, 2015
Re-energised, the New Zealanders negotiated another early flurry before putting the hurt on.
They ran in another five tries and won out 47-9 to top their pool.
We hope Joe Schmidt was taking note.
