Work has begun on demolishing the Tricorn Centre, dubbed the UK's ugliest building in a poll on BBC Radio 4.
Portsmouth resident Stuart Hamilton won a council competition to start the bulldozers to demolish the city's notorious 1960s landmark.
Mr Hamilton began the demolition, which will take 10 months, at 1100 GMT.
Supporters this month failed to get listed building status for the Tricorn, which has lain empty for nearly 30 years and been derelict for 15.
The start of the work was accompanied by a rendition of Tchaikovsky's 1812 overture.
The piece was chosen by Portsmouth City Council because in the 1960s - when it won design awards - the building was described as "an orchestration in reinforced concrete that is the equivalent of the 1812
Britain's 'most hated'
Earlier this year the Department of Culture, Media and Sport said most people wanted it torn down.
The building topped a 2001 poll by Radio 4's Today programme to find Britain's most hated building, with one listener describing it as "another 1960s consumer rat-maze".
Heritage Minister Andrew McIntosh said earlier this month that the Tricorn did not meet the criteria to be added to the national statutory list.
"I know that the Tricorn Centre is the subject of strong local feeling but, while an interesting building, I have decided that it does not possess the degree of special significance required for listing," he said.
Portsmouth City Council said the decision cleared the way for the site to be demolished for a new shopping complex planned.
Owen Luder, the architect who designed the Tricorn, has criticised the council for rejecting a plan to regenerate the building and turn part of it into flats.
Protestors from the Portsmouth Society, which wanted to keep the centre, turned out to see the demolition work begin.