Chorus says data traffic on its network reached a new peak of 3.15 terabits per second on Thursday night.
Previous peaks have been hit during the 2019 Rugby World Cup and the first week of Level 4 lookdown - but Thursday's spike coincided with the global release of chapter two, season four, of popular online game, Fortnite.
The Fortnite frenzy passed the network's previous peak of 3.07Tbps recorded on Saturday 15 August, also coinciding with an update to the online game, Call of Duty.
Chorus - which operates the lion's share of UFB fibre - says there was no congestion. Its network ceiling is around 3.5Tbps.