Cradling candles, laying wreaths and clad in black or white, Hong Kong residents transformed a downtown park into a speckled sea of flickering lights, in remembrance of the hundreds of pro-democracy demonstrators and students crushed by tanks and troops near the square two decades ago.
While China has tried to whitewash the incident over the past two decades and has tightened security around Tiananmen Square in recent days, Hong Kong has long made the most of its unique freedoms to openly challenge Beijing to reverse its verdict on June 4 and fully account for the killings.
Many in Hong Kong acknowledge China's economic progress since 1989, but still find the memories of June 4 impossible to forget.
I know China is improving, but I hope that they will admit that they fired guns and did wrong, said Kong Choi-fung, a 44-year-old church worker who took her two children to the vigil.
A British colony until 1997 when Hong Kong switched to Chinese rule, the city has enjoyed wide-ranging freedoms of expression denied most people in mainland China. But China has delayed calls for direct elections till 2017 at the earliest.
This year, painful memories have been accentuated in the city by political controversy and the symbolic 20th anniversary.
The memoirs of former Communist Party Chief Zhao Ziyang, who sided with the 1989 demonstrators, has been a publishing sensation, with some of his voice recordings played at the vigil.
Donald Tsang, the city's chief executive, sparked a mass walkout of pro-democracy lawmakers at a recent legislative session by suggesting most Hong Kong people wanted to reassess June 4, given China's great economic progress since then.
People in the crowd, however, wore T-shirts and headbands with the rebuke: Donald Tsang you don't represent me.
The vigil also saw the rare appearance of a Chinese student leader from 1989, Xiong Yan, who was able to enter Hong Kong over the weekend. Other Chinese June 4 dissidents suh as Yang Jianli and Xiang Xiaoji were turned away ahead of the anniversary.
Hong Kong is a part of China and can influence China more than any country, more than any place, said Xiong, who was one of 21 people placed on Beijing's most wanted list in 1989.
I heard a lot of people came down from China tonight. They want to experience this. That's great ... where there is freedom, there is the meaning of life, he told Reuters.