Neither early voting nor postal voting is allowed in the territory- a limiting rule which drove a number of voters to fly in from different parts of the world in hopes of taking part in the critical decision that will greatly affect Hong Kong's future.
A recount in one remaining constituency held up the final result and was continuing Monday afternoon. A spate of incidents, including the disappearance of five Hong Kong booksellers who later resurfaced in mainland Chinese detention, has aroused fears that Beijing is reneging on its promise of wide autonomy for Hong Kong under a "one country, two systems" framework.
Leading Hong Kong pro-democracy activist Nathan Law has said he will not use his newly-won seat on the Legislative Council (LegCo) to push for independence from China.
It said some candidates had used the election as a platform to "openly promote" independence, adding that went against China's constitution, as well as Hong Kong's own mini-constitution, known as the Basic Law.
The pro-democracy candidates needed to secure at least 24 of the 70 total seats to be able to block government attempts to pass legislation.
Following the record-breaking election, the Chinese government issued its "firm opposition" to any pro-independence activities, either on the council or outside of it, and warned that they will impose punishment in accordance with the law on legislatures who back independence.
Several young activists who oppose China's control over Hong Kong have been elected to the territory's legislature in a sign of growing political polarisation and anger with Beijing.
Before Sunday's election, the Hong Kong government halted the candidacy of six politicians who were accused of having called for independence and it has threatened to take "follow-up action" against other candidates who support the idea.
They include Nathan Law, a 23-year-old who played a prominent role in 2014's "Umbrella Protests" and co-founded the Demosisto Party with well-known activist Joshua Wong.
At some polling stations there were long queues until until 2:30am on Monday morning - four hours later than the scheduled cut-off time - with a turnout of nearly 60% of 3.7 million voters.
Several veteran democrats failed to retain their seats, as voters backed a new batch of younger democrats espousing self-determination and a more confrontational stance with China. "Young people have a feeling of urgency when it comes to the future". "We still have to unite to have stronger power to fight against the Chinese Communist Party". That now seems unlikely, because the candidate he supported, Sixtus Leung of the Youngspiration party, won a seat.
The Legislative Council - or the LegCo - election were the biggest polls held after the 2014's mass protests calling for greater autonomy from China.
They are becoming increasingly anxious that Beijing is moving to erode the territory's civil liberties, which are enshrined under the 1997 handover agreement that ensured Hong Kong's autonomy for at least 50 years.
The pro-democracy camp now controls 27 of 70 seats, and must keep at least a third of the seats to retain veto power. However, only 35 seats are directly elected by the constituents.