Farr-Jones believed Genia - who engineered Saturday's match-winning try with a sharp break - had the All Blacks running scared.
"Will Genia, we all know is without doubt the best scrumhalf in the world, but I'd say leading into the World Cup, along with (All Black playmaker) Dan Carter he is the most valuable player that any team has,'' Farr-Jones said.
"No disrespect to Phipps or Burgess but if I woke and found out that Genia had a tournament-ending injury then I'd almost give up on the Wallabies' hopes - he is that good.''
He believed 23-year-old Genia would rank alongside Catchpole as Australia's best halfback within five years.
But Farr-Jones insisted World Cup hosts New Zealand remain deserved title favourites for the tournament starting in nine days.
He recalled Australia losing 6-3 to New Zealand just before the 1991 World Cup and feared the All Blacks loss in Brisbane could galvanise them.
"The All Blacks probably had the loss they had to have,'' Farr-Jones said.
"I still think they start as clear favourites to win and they will have that steely determination and in a way, I think their nation deserves it.
"They are a wonderful rugby nation.''
- AAP