Moss got his marching orders in the 59th minute apparently for dissent after he approached referee Lencie Fred of Vanuatu to talk about a goalmouth incident.
Following a challenge by Osea Vakatalesau on James Pritchett, Moss went to talk to Fred after the ball was cleared out of play.
He was flashed the red card when he persisted with talking to Fred after he was asked to move away.
The match held little significance because New Zealand have already been crowned Oceania Nations Cup champions and qualified for the against the fifth-best Asian qualifier for a place in the World Cup finals in South Africa in 2010.
New Zealand fielded a "development" side shorn of senior stars such as Shane Smeltz, and overseas-based players Ryan Nelsen and Chris Killen.
The first half saw no goals with New Zealand missing a number of chances.
Nippy winger Leo Bertos delivered a cross in the second minute which Jeremy Brockie head over the bar and a Jeremy Christie drive sailed over the bar six minutes later.
Steven Old's shot from 18 metres grazed the top of the cross bar 10 minutes later and then a Greg Draper header looped over the Fiji goalkeeper only to strike a post .
Fiji, using just Roy Krishna upfront, hardly troubled the New Zealand goal.
New Zealand had the majority of the possession in the first half but were unable to convert any of their chances.
But once Moss was sent off, coach Ricki Herbert was forced bring on reserve goalie Jacob Spoonley and take Greg Draper off.
Within four minutes, Krishna struck the opening goal, running into the box and beating Spoonley with a low and hard shot into the net.
With an under-strength New Zealand chasing the game, Fiji found more gaps to exploit and Krishna, taking a cross from the right, went round Old to rifle home his second goal from inside the six-metre box in the 90th minute.
Herbert said his side, who had about 80 percent of possession, should have converted a number of chances, but added it had been a good grounding for young players such as Costa Barbarouses and Jeremy Brockie filled the strikers' roles.
He thought Moss had been sent off for something he said to the referee but declined to comment on the referee's decision.
He was unsure if he would lose Moss to further sanctions over the red card for the Confederations Cup tournament or the World Cup qualifier next year.
Fiji 2 (Roy Krishna 2) New Zealand 0. Halftime: 0-0
