The District Council election on Sunday was the first opportunity to measure popular support for democracy since massive public protests rocked Chief Executive Tung Chee-hwa's government in July.
However few analysts predicted the rout inflicted on the Democratic Alliance for the Betterment of Hong Kong (DAB), which supported a controversial security bill demanded by Beijing which triggered the protests.
Democratic Party Chairman Yeung Sum said the results sent "a clear message to Tung Chee-hwa and the Chinese government that the public wants full democracy."
He called for universal suffrage to elect the chief executive in 2007 and the Legislative Council elections in 2008.
The Democratic Party claimed 93 seats - compared to 86 seats in 1999 - while the DAB won just 64 seats compared to 83 at the last elections. A total of 400 seats were elected, but only 326 were contested.
The elections also attracted record voter numbers and turn-out rates with more than one million people, or 44.04% of eligible voters, casting their ballots.
Tung, who is currently hand-picked by an 800-member committee, oversees a partially elected legislature.
Before the 1 July rally "most people would have forecast a solid win for DAB and a heavy defeat for the pro-democracy parties"
political analyst, City University, Hong Kong
A poll conducted by the Hong Kong university of 2,200 people at the polls on Sunday found that 34% cited the 1 July rally as the reason for giving them the incentive to vote. More than 500,000 people marched at the rally against a security bill that was later withdrawn.
Yeung said the turnout at the elections for the councils, which act as advisory bodies and have limited powers, indicated turnout for September elections for the more powerful Legislative Council would be higher.
Defeated DAB chairman Tsang Yok-shing offered to resign, saying his party had suffered from fostering close ties with the government. The party is to meet next week to discuss the results and Tsang's future.
Joseph Cheng, a political analyst at City University, said that before the 1 July rally, "most people would have forecast a solid win for DAB and a heavy defeat for the pro-democracy parties".
But the overwhelming nature of the victory showed the public now wanted constitutional change.