"They said that they wanted a catch-up with us to do an interview because we got into the top three," said Ms Webb.
"They came over and asked us to invite some good close friends around who could also be interviewed.
"After a good 20 minutes the questions came right down to the nitty gritty and I thought it was definitely just an interview.
"Then a group of people came around the corner from Turtle Island, singing and with flowers in their hair and it wasn't until they said 'congratulations' that we knew."
Mr Armstrong said he was speechless at the announcement, but the couple wanted to thank those who had voted for them.
The director of marketing at the Fiji resort, Matt Buchan, said he was surprised to find the couple had beaten their US and Australian-based competition.
"Aveael and Murray weren't the only couple to get media support and promotion but clearly New Zealand got behind them 100 per cent," he said.
They will wed over Valentine's Day weekend.
Watch the video here:
Entry for Turtle Island Horse Riding at Sunset Beach on my Birthday from Aveael Webb on Vimeo.