The Greens have retained the St Peter and North Laine seat in the Brighton and Hove City Council by-election.
Lizzie Deane took 1816 votes in the by-election on Thursday, beating Labour’s 24-year-old student Tom French into second place with 880 votes.
Conservative candidate Rob Buckwell won 365 votes, Liberal Democrat candidate Trefor Hunter got 103 and independent candidate Gerald O’Brien recorded 32 votes.
Turn-out for the by-election was low at just over 24%.
The result means the Greens have held onto the seat vacated by Keith Taylor and maintained their position as joint second largest party on the council.
The by-election was called when Mr Taylor resigned after 11 years on the council to take up a seat as an MEP – the position vacated by Brighton Pavilion MP Caroline Lucas.
Coun Deane said: “I would like to thank the voters for putting their faith in me to represent them as a councillor.
“I look forward to representing the people of St Peter and North Laine. We look forward to increasing our number of councillors.”
She had pledged to try and protect urban green spaces, reduce traffic and improve air quality during her campaign.
After the result was announced at about 11.45pm Mr French called on the Greens to work in coalition with Labour councillors to “oust the Tories” but admitted it was unlikely.
He added: “I am really proud of all our campaigners – ordinary Brighton people who love the city and want to improve it.”
Mr Buckwell said: “I think our vote share held up quite well. It was a positive campaign but we always knew it was a difficult seat.”
It is the latest victory for the Green Party in the city after Dr Lucas became MP and Alex Phillips took the Goldsmid ward from the Conservatives at the last by-election in July.
Both Labour and the Greens have 13 seats and the Conservatives remain a minority administration with 25 seats.
The Liberal Democrats have two councillors.