The Greens are celebrating an election victory in the ultra-marginal Prahran electorate after fending off both Labor and Liberal challengers.

Incumbent MP Sam Hibbins will join two other Greens MPs in the Victorian Parliament’s lower house, with the party now retaining the same number of seats as it had before the election.

Sam Hibbins campaigning on election day. Credit:Chris Hopkins

Prahran is among the last electorates where victory has been claimed due to the small number of votes separating the candidates. It was previously the most marginal seat in the state with the Greens holding it by 0.4 per cent before the recent election.

While the results are yet to be finalised by the Victorian Electoral Commission, Labor's Neil Pharaoh tweeted a concession on Tuesday.