A Vector spokeswoman said the it affected 20 Vector customers from 464 to 498 New North Rd, which are on one side of the street.
Three generators were escorted by police to the area after it was decided that fixing the faulty transformer would take too long.
The affected section of New North Rd was reduced to one lane because the generators took up so much room.
By 7.35pm, all the firms had the power back on, although Vector had to bring in a fourth generator to power The Kingslander's chillers. It was operational by 8pm.
Sarah Emery, manager of the tavern, one of Auckland's top rugby-viewing venues, said the loss of power would mean loss of income "big time".
"This is the ultimate sports venue, and we're so close to Eden Park, and if you haven't got a ticket this is the place to watch the game. And now it's all going down the toilet."
Ian Lines, owner of the Taiko Japanese restaurant, said he was forced to turn away bookings after the power failure plunged his eatery into darkness.
"We've been planning this night for months," said Mr Lines. "And now we've lost a lot of money.
"People have been pretty uncomfortable, but they're singing, cheering, making the most of it."
- additional reporting: APNZ