Greens federal MP Adam Bandt, Victorian MP-elect Ellen Sandell and federal senators Richard Di Natale and Sarah Hanson-Young pose for a selfie

The dust is taking a while to settle on the Victorian election, thanks to an unprecedented deluge of pre-poll votes and a more cautious attitude on the part of electoral authorities since the Western Australian Senate election fiasco last September.

However, one particularly momentous result has been nailed down since election night — the Greens’ win in Melbourne, making 30-year-old Ellen Sandell the party’s first member of Victoria’s lower house.

The Greens claimed victory in the seat on Saturday night, but this was left looking premature after the counting of postal votes later in the evening tilted the balance back to Labor.

The uncertainty prompted the Victorian Electoral Commission to attend to the electorate’s pre-poll votes as one of its earliest priorities after election night. But far from riding to Labor’s rescue, these piled a decisive 358 votes onto the Greens lead, causing Labor member Jennifer Kanis to concede defeat yesterday.

Sandell’s win comes as a great relief to a party that has been banging its head against the Legislative Assembly wall since its electoral breakthrough in 2002, a failure that was particularly demoralising given Adam Bandt’s success in clearing the seemingly higher bar set by the federal seat of Melbourne in 2010 and 2013.

The Greens can also boast of having cut Labor margins in the other three seats of their inner-city heartland, Richmond, Brunswick and Northcote, and of adding a fifth seat to their future wish list in Prahran, where a slightly higher primary vote might have allowed their candidate to unseat the Liberal incumbent on Labor preferences.

For the time being, the ongoing presence of traditional Labor-supporting demographics in these electorates, such as the Vietnamese enclave in northern Richmond and the strong Greek communities of Northcote and Brunswick, cause them to be tougher nuts to crack.

By contrast, Melbourne’s distinguishing feature is the youngest median age of any electorate in the state — 29, compared with 34 in Richmond and Brunswick, 36 in Northcote and 37 statewide — and, relatedly, the highest proportion of tertiary students.

Another factor playing to the Greens’ advantage was the redistribution, itself symptomatic of demographic transformation in that a swelling population caused it to lose territory at its north-western end.

Of particular disadvantage to Labor was the loss of over 5000 voters in Flemington and Travancore, located to the west of a CityLink motorway that marks a dividing line between the inner-city and Labor’s bastions of the northern and western suburbs.

With the gain of Melbourne supplemented by the expansion of the Greens’ upper house domain from three seats to four or possibly five, the party would seem to have a fair deal to crow about.

But none of this is apparent if we step back and look at the statewide primary vote, on which the Greens have made no headway at all on their 11.2% showing in 2010 — the first Victorian state election of which this could be said, since the party first fielded a handful of candidates in 1992.

What the result instead points to is a widening in the gap between the inner-city bohemia that delivered a critical mass of support in Melbourne and the suburban and regional marginal seats that constitute the battleground between Labor and Liberal.

As such, the result bodes well for the party’s longer-term prospects in maintaining the federal seat of Melbourne as a permanent fixture, of continuing to strengthen in the inner-city Sydney state seats of Balmain and Marrickville, and of securing the corresponding federal seat of Grayndler when the eventual retirement of Labor Left stalwart Anthony Albanese makes it winnable for them.

But as encouraging as all that may be, it remains an open question whether the Greens will be the beneficiary of an ongoing process of disaffection with the two-party system, or if the low double figures represents a ceiling of support for a party locked outside the process of government formation.