Coach Marc Lievremont dropped his regular five-eighths Francois Trinh-Duc for the game which should decide the winner of Pool A.
The French coach has paired the 31-year-old Yachvili and 22-year-old Parra although there is every indication it is a ploy to light a fire under Trinh-Duc's tepid formline.
This will be the first time Yachvili and Parra have started a test together, although they had short bursts against Japan and Canada in this World Cup.
"We can play nine and 10 during the game, so we stop asking questions and do it by instinct," Yachvili said.
Lievremont could have played Damien Traille at five-eighths, but decided to leave him at fullback and use both his versatile halfbacks.
He has picked four players - captain Thierry Dusautoir, Julien Bonnaire, Vincent Clerc and Traille - who began the 18-20 shock win against the All Blacks at the last World Cup and the All Blacks are likely to respond with a similar number.
Yachvili rejected suggestions France were always confident about tipping up their hosts. They might look assured, he said, but inside the French were churning about the task ahead of them at Eden Park.
"It is always a special game but very hard to win against them," Yachvili said.
France were the last team to tip over the All Blacks at Eden Park when they beat them in 1994 with the 'try from the end of the earth'.
"We were very proud of that, but it was a long time ago.
"We have talent, we are here, we train hard to achieve that. Why not on Saturday?"
France had shared the series in New Zealand two years ago, Yachvili said, but this week was an unknown.
France wanted to win every game, Yachvili said. They had never thought about "throwing" the test.
"The test between Ireland and Australia told us what can happen," Yachvili said. The key for France would be the work of their forwards, he said. Ireland had showed them the recipe for success.
"Maybe we are good against New Zealand because we are more afraid against the All Blacks than England, sometimes that fear works for you, the bete noir we say in French."