Nearly one million people tuned in to watch Team New Zealand's nail-biting efforts on Sunday morning - more than 16 times the number of viewers who normally watch TV One during that time slot.
Sunday usually averages 56,000 viewers between 8am and 10am but between 8.15am and 8.45am, the channel had an average audience of 927,000, which was the highest number for all races last week.
That figure dropped to 900,000 for the second race that morning in the 9.15am to 9.45am slot, despite it being postponed.
The channel had 77 per cent of the audience share over all New Zealand channels at that time.
TVNZ's head of television, Jeff Latch, said he was excited by the record numbers.
"New Zealanders are completely gripped by the America's Cup. Record numbers tuned into TV One's coverage on Sunday morning - close to a million people, which was over three-quarters of people watching TV at that time. We're thrilled."
He said multi-screening - where people started watching races at home on TV and then picked up coverage elsewhere throughout the day - was more popular during the weekdays.
Mr Latch said yesterday's race saw the network's biggest day for live streaming with 166,320 streams.
He said live streaming on smartphones, tablets and PCs had "brought an exciting new dimension to race coverage".
Herald head of news and online editor Cathy O'Sullivan said interest had continued on nzherald.co.nz, with the event dominating the five most-read sports stories across all platforms.