Global Frontier, with a gross tonnage of 33,226, had to approach Dunedin on the top of the tide during daylight and when wind conditions were suitably calm.
It was also escorted from Port Chalmers by a tug boat.
Port Otago chief executive Geoff Plunket said, although Global Frontier was the largest vessel to pass through the upper harbour, it held the record by a slim margin.
It was 190m long, 32.29m wide and carried about 16,000 tonnes of cargo to be discharged.
The second largest vessel, Tenor, negotiated Victoria Channel on September 17, 2010.
Its gross tonnage was 32,837, length 189.99m and width 32m.
Mr Plunket said both vessels were at the extreme end of the scale of what could pass through upper Otago Harbour.
Global Frontier would sail from Dunedin on Monday, he said.
