The contest in Holland-Bukit Timah GRC this election had looked like a close fight but turned out to be a rout. Residents, who initially gave a warm reception to the Singapore Democratic Party (SDP), handed the incumbent People's Action Party (PAP) team a resounding 66.62 per cent of the vote last night, improving its performance by a good 6 percentage points compared with the last elections.

Minister for the Environment and Water Resources Vivian Balakrishnan, who led the four-member PAP team comprising Minister of State Sim Ann, banker Liang Eng Hwa and lawyer Christopher de Souza, told reporters at Jurong West Stadium last night: "I see this as an investment of hard work and relationship building, which takes years, not something which you do over nine days."

The win was also significant because residents of private and public housing estates voted the same way, he said.

"We are a unique GRC in the sense that we have the highest percentage of private estates. And I'm very pleased to see that this was one outcome in which both residents in private estates as well as the HDB estates gave us a resounding victory, and there was no divergence, there was no difference.

"So this speaks well for the unity and cohesion for Singapore."

Over at the SDP headquarters in Ang Mo Kio, an upbeat SDP secretary-general Chee Soon Juan had told reporters before counting began: "The mood is different… Then again with the advent of social media, things are opening up and people are learning to be a bit more comfortable in their own skin and really excited about the voting process as well."

But the mood turned grimmer when sample votes showed the SDP comfortably beaten. A stoic-looking Dr Chee said at the press conference called at about 2am: "We are proud of the fact that we ran a disciplined and positive campaign... Despite everything that has happened, the opposition still labours under a very undemocratic system."

Dr Chee's team - which included National University of Singapore Yong Loo Lin School of Medicine professor Paul Tambyah, compliance auditor Sidek Mallek and healthcare administrator Chong Wai Fung - was widely considered SDP's strongest among the two GRCs and three SMCs it was contesting in.

Yet its vote share slid from 39.9 per cent in 2011 to 33.38 per cent last night, marking a disappointing return to the polls for Dr Chee.

He had been forced to sit out the past two elections after being made bankrupt by defamation suits brought against him by PAP leaders, and managed to get his bankruptcy annulled only in 2012.

It was an election that the SDP had geared up for early. It launched its campaign in January, way before elections were called.

During the hustings, the SDP focused on a range of alternative housing, retirement and healthcare policies that it had churned out in recent years. These included a national minimum wage, a health investment fund as well as cheaper public housing if the units were not resold on the open market.

And some of these policies did sound attractive, say residents.

Dr Balakrishnan, who has argued that the proposals are not financially sound, told reporters: "Well I think the voters have cast their judgment on their policies. And I think we'll move on from there."

Mr Ching Jianhong, 33, an instructor at Duke-NUS Graduate Medical School, said: "I would say that Dr Paul Tambyah's arguments on the medical issues are good." But the results are "quite expected", he noted. "Given Dr Chee's past record, the PAP stood a higher chance."

Dr Chee has been fined and jailed for various acts of civil disobedience in the past. The PAP team raised the issue of his past infractions right from the start of campaigning, something which the SDP dismissed as an attempt to distract voters from the real issues.

• Additional reporting by Rennie Whang and Nur Idayu Suparto