Sorn Yin, President of the NSW Khmer Community' who was a teacher when Pol Pot's brutal Khmer Rouge regime took hold of Cambodia, delivered an emotional eulogy.
"All of us suffered unimaginable cruelty in those years," he said.
"From Cambodia, we escaped to refugee camps in Thailand where we waited anxiously for the chance of re-settlement. The Hawke government warmly welcomed us to Australia."
"I will always be grateful to him and to his government for giving my family a chance to live in peace and freedom."
It was in 1983 when Bob Hawke became Prime Minister that most of the refugees present at the service arrived in Australia.
More than 3,000 were welcomed in that year alone.
Source: Abbie O'Brien/SBS
Sina Nou was among them.
"He's my father," she said holding back tears.
"He give a good life for all Cambodian people."
Sorphy Bun also arrived that year.
"My life completely changed," she told SBS.
"He gave us a new life and we want to pay respect for what he's done for us and our community."
Touched by news of the memorial, Bob Hawke's widow Blanche d'Alpuget asked if she could attend.
The community welcomed her with open arms by including her in the traditional ritual, which involved laying flowers and lighting candles.
Labor MP Craig Emerson - once a senior adviser to Bob Hawke - was also in attendance.
So too was Chris Bowen whose Sydney electorate has a large Cambodian population.
"They love him. They just love him," he told SBS News.
"You saw the emotion in the speeches, the President of the Khmer community breaking down while he was eulogising Bob Hawke -- they know that the world, Australia, would be a very different place without a Bob Hawke prime ministership.
"He knew that those refugees who came to Australia under his watch went on to not only get refuge in Australia but to make a contribution to our country -- and their children."
The community expressed gratitude to Bob Hawke for allowing them to flourish in Australia.
"The Hawke government did everything it could to help us become independent. We stayed in migrant hostels when we first arrived. Settlement services and NGOs helped us set up our own households and helped us find work," said Mr Yin.
"We had access to doctors through Medicare. There were English classes for adults and when our children started school, they attended special classes to help them learn English."
Chantha Pinchanron said he helped weave the social fabric of the community.
"If it wasn't for Bob Hawke, we don't have the temple, we don't have the place where we can get together and have the community socialise and make events."
The service also honoured the instrumental role the Hawke government played in restoring democracy in their homeland in 1991.
"It is Australia's role in bringing democracy to Cambodia that is the closest to the hearts of everyone here today. We are grateful to Prime Minister Hawke for caring about our country and for the years of patient negotiation that led up to the Paris Peace Accords," said Mr Yin.
Nearly three decades on, however, critics say those freedoms are increasingly under threat.
But there is still hope, said Chris Bowen.
"There is one more thing we can do to honour him. And that is to keep working for democracy and peace in Cambodia."