With about 60% of votes counted almost six hours after polls closed on Sunday, the pro-democracy camp had extended its presence by three seats to 25 in the 60-seat Legislative Council.
The count involved only the 30 directly elected seats in the legislature; the rest will be decided by a small number of privileged corporate and middle class voters who traditionally back pro-Beijing candidates.
Blaming the movement's poorer than expected showing on a rash of scandals before the election, democratic leaders said they had hoped for a bigger win.
"I am not happy with that," said a terse Martin Lee, the movement's veteran figurehead, after exit polls failed to predict a democrat landslide.
Nearly 53% or 1.7 million of the 3.2 registered voters had turned out, the highest number of ballots cast in any election in Hong Kong.
But Yeung Sum, chairman of the Democratic Party, the pro-democracy camp's prime organisation, put a brave face on things.
"We would have liked to get more seats, obviously, but we appear to have won a majority of the vote, so we are pleased with that," Yeung said.
Sunday's election was being seen as a referendum on the city's feelings towards China after 14 months of turmoil when Beijing was accused of interfering in the running of the city.
Hong Kong has been a largely self-governing enclave since China took control from colonial ruler Britain in 1997.