Tom Slingsby says it was either collide with a mark or possibly kill someone on Australia's disastrous day at the SailGP series event in Christchurch.

Australia's Flying Roo suffered damage in the first fleet race of the day and took no further part in the competition.

New Zealand took full advantage of Australia's mishap, going on to win the ninth leg of the series and lead the championship standings.

The Australians were docked eight points and now trail the Kiwis by nine overall after being deemed at fault for the collision.

But driver Slingsby says it was either hit the mark or possibly kill someone on a Canadian boat.

Australia and Canada were approaching the first mark at speed and on a collision course.

Slingsby manoeuvred to avoid a crash and Australia's Flying Roo hit the course mark, causing irreparable damage to the front beam and further damage to the port hull and board case.

"It all happened so quickly ... I knew that we were going to hit Canada so I had a choice to make," Slingsby said.

"I wanted to keep people safe so I turned the boat as hard as I could into the course mark.

"I knew the mark was there but It was either that or go straight through Canada.

"I am just happy that no one was hurt ... I don't think it has all sunk in.

"It's been pretty emotional for me, it is a really scary moment when you feel like you could kill someone."

Only two events remain in Bermuda and Halifax before the series final in New York in June.

The latest leg on Lyttelton Harbour near Christchurch on the South Island was condensed to three fleet races before New Zealand, France and Canada raced in the event final.

New Zealand, France and Canada each won one of the fleet races sailed Sunday to qualify for the final in which New Zealand beat France by 12 seconds.

The home side sailed cleanly throughout the day, often choosing to race out of phase with the remainder of the fleet to avoid the danger of a collision.

There were multiple collisions in the first race which was won by New Zealand with Canada winning the second and France the third.

The third race was thrilling as several teams vied for a place in the final - only the top three teams contest the final and the winner is crowned the event champion, taking 10 points in the overall series standings.

France, Canada, Spain and Germany led early in the third race before New Zealand closed into fourth place at the fifth gate and finally moved up into second.

New Zealand won the start in the final and led around the course. Canada was second early but lost ground when it split with the fleet on the third of seven legs.

The race win was the third in succession for New Zealand driver Peter Burling who steered the New Zealand boat into first placings in Dubai and Abu Dhabi.