More than 420 New Zealand firefighters, representing more than 100 brigades, as well as firefighters from Australia and the United States raced up 51 flights - a total of 1103 stairs - to the top of the Sky Tower in the seventh annual Firefighter SkyTower Challenge.
It was the first time the 29-year-old had entered the event, which she won in a time of 13min 28sec, ahead of previous titleholder Maree Ryan, who finished in 14min 5sec.
Paul Gerritsen, of Remuera Station, was first, finishing in record time of 9min 35sec.
Miss Gray joined the Queenstown volunteer brigade about nine months ago, after settling in the resort, and in doing so, carried on a family tradition.
Her grandfather was also a "voly" and her great-grandfather was the chief fire officer for a North Island brigade.
Not long after signing up in Queenstown, she heard about the SkyTower Challenge and decided to enter.
"I decided to enter and did a bit of training for it - I didn't intend to win it, I just wanted to do it."
Miss Gray's training involved running up to the Skyline and running stairs at One Mile - which she had climb up and down 16 times to come close to the distance of the Sky Tower.
"I didn't know what it was like to just go up. I didn't know how hard to push.
"It's been going for seven years and apparently [my time] is the record.
"I'm not quite sure how I managed that.
"When I got to the top, I thought I probably could have pushed myself a bit harder, because you don't know how much fuel you've got in the tank.
"I'm a fairly competitive person anyway, but I didn't set out to win it. It was more about being able to say I've been up the Sky Tower stairs, and raising money for the Leukaemia and Blood Foundation.
"One of the members of the Frankton brigade told me if I could do it in under 18min he would buy me a drink, so that became the goal.
"I'm still waiting on that one."
Making her feat even more impressive was that Miss Gray was "donned and started", meaning she wore the 25kg uniform - half of her weight - and used breathing apparatus during the event, despite suffering from a back injury.
Miss Gray would "hopefully" be back to defend her title in 2011.
In total, $193,000 was raised for the Leukaemia and Blood Foundation.
