Team New Zealand have pulled out of the second race of the America's Cup challenger series final with an electric gear failure, leaving their best-of-13 match against Luna Rossa locked at 1-1.
The Italian syndicate completed the course on San Francisco Bay to lodge their first win over the New Zealand outfit since the Louis Vuitton Cup series began six weeks ago.
Strong winds forced the day's second race to be called off, leaving the final all-square after two days dominated by boat malfunctions.
Team NZ were about 400m ahead as they approached the third mark on Sunday when they suddenly slowed because of a hydraulic fault which prevented the boat from tacking or gibing.
Skipper Dean Barker says they were "crippled" when the electric system that controls the hydraulics of the daggerboard failed inexplicably.
"It's the nature of these boats unfortunately - there are so many things that can go wrong and today it was a problem with the hydraulics," Team NZ skipper Dean Barker said.
"We have been very fortunate so far not to have had many issues until today but I guess this just reinforces the need to be 100 per cent."
Support staff boarded the boat and had repaired the problem ahead of race three, which was subsequently postponed.
It is unclear if the issue was related to a spectacular incident in race one on Saturday in which Team NZ nosedived at high speed, sending two sailors overboard.
Team officials played down the significance of that incident, which damaged carbon fibre fairings.
The New Zealanders went on to win race one after Luna Rossa suffered daggerboard damage.
As has been the case throughout the regatta, New Zealand dominated the start on Sunday, opening up a lead of 23 seconds by the second mark before their problem struck.
Luna Rossa helmsman Chris Draper was happy to secure his team's first win.
He says rough conditions and intense racing schedule are contributing towards the breakages.
"We're pushing the boats and loading the wings up way harder," he said.
Race three and four are scheduled to be sailed on Monday.
Earlier, it was the turn of America's Cup holders Team Oracle USA to suffer damage to one of their two boats.
A boat skippered by Ben Ainslie was forced to limp back to the team base after snapping a rudder.
Oracle say the incident was the result of a damage caused a day before, when the boat tangled with a buoy.
Oracle will defend the America's Cup next month against either Team NZ or Luna Rossa.
