Symon defied the national trend by retaining the marginal seat in Melbourne's eastern suburbs with a slight swing in his favour of just under one per cent after preferences.
"Deakin is over the line," Mr Symon told AAP with 77 per cent of the vote counted.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Symon took a tight 1.4 per cent margin into the poll after taking the seat from the Liberals in 2007 and became the first Labor member to retain Deakin in history.
He said he was helped by the fact Prime Minister Julia Gillard is Victorian.
"I think it comes down to a bit of Victorian parochialism, Julia being Victorian," he said.
"But it also comes down to dealing with the issues in the local electorate. I was able to go back to the electorate and say 'this is what I promised and this is what I've done'.
"And we've got a very good state government. It's a different political environment than it is in Queensland and Victoria."
The Australian Electoral Commission predicts Mr Symon will take 52.2 per cent of the vote on a two-party preferred basis, while Liberal candidate Phil Barresi, who held the seat from 1996 to 2007, will claim 47.8.
