The ORMA60 TVS dropped her wing mast rig in the early stages of a Wednesday evening race, on Auckland's Waitemata harbour.
The trimaran was reported to be flying two hulls and travelling at over 25kts when a shroud gave way.
She was leading the race at the time, but was being pursued by the prototype AC45 sailed by Team New Zealand skipper Dean Barker at the time time of the incident. The AC45 was reported to be catching TVS, but had not yet passed her.
No injuries were reported to the crew, and damage to the wingsail is also reported to be minimal.
After the incident the wing mast was still afloat as was towed back by two Emirates team NZ tenders who were quickly on the scene.