The Liberal Democrats have won the Sunderland City Council seat previously held by the late Paul Watson.
Labour politician Mr Watson passed away in November aged 63 after serving the Pallion ward since 1997.
He had been leader of the council since 2008.
A by-election which was announced following Mr Watson's death was held yesterday and saw the Lib Dems' Martin Haswell win the seat with 1,251 votes, while Labour's Gordon Robert Chalk was second with 807.
The Conservatives' Grant Shearer came third with 126 votes, UKIP's John Steven John Bewick got 97 votes while the Green Party's Craig John Hardy polled 39 votes.
A delighted Coun Haswell told the Echo: "We've had very long day but we're over the moon with the result.
"We've had over 10,000 door knocks in three months so a lot of hard work has gone into this.
"We've had an impressive turnout and a big switch to people voting for our party.
"It is an indictment of how unhappy people in this area are at how they have been treated in recent years.
“I wanted to stand for election where I live because our area needs a local champion.
"Like lots of places in Sunderland, Pallion and Ford Estate have been dominated by the Labour Party for decades and have nothing to show for it.”
“People round here are fed up with the rotten and complacent Labour establishment which has taken residents for granted for years.
"I want to be a different sort of local councillor – one who keeps in touch, helps people out, and gets things done all year round.
"I’m really grateful to the residents of Pallion, Ford, Pennywell, St Gabriel’s, High Barnes and Hylton Lane Estate for putting their faith in me, and I’m looking forward to getting to work."
Niall Hodson, leader of the Liberal Democrats on Sunderland City Council added: "This result ought to terrify Sunderland Labour.
"They know the result in Pallion and Ford Estate shows that even in their so-called safest strongholds, people are fed up with the way they run the city and the council – refusing to listen to or consult with local people, and arrogantly expecting their votes at election time.
"UKIP have imploded, and the Conservatives were nowhere and had nothing to say.
"The Liberal revival in Sunderland continues apace and we have proved we are now the real opposition, a growing political force in the city, and a serious threat to Labour in May’s local elections."