Local shares failed to hold on to early gains and headed south on Wednesday after heavyweights faltered upon their return from a long weekend.
The Hang Seng Index opened up 162 points, but soon reversed course to dip into negative territory.
It finished down 263 points, or 0.9 percent, at 28,674, on turnover of HK$171 billion.
Heavyweight Tencent slumped 3.7 percent. Meituan and Hong Kong Exchanges and Clearing each fell 2.4 percent. AIA and Alibaba each gave up 1.6 percent.
The biggest blue-chip loser for the day was Haidilao. The mainland hotpot chain plunged 5.6 percent.
But pork producer WH Group and Budweiser APAC each jumped more than 2.5 percent to become the top performers on the benchmark.
Markets across the border also ended in the red, weighed by consumer shares. The Shanghai Composite shed 0.1 percent, while the blue-chip CSI300 index declined 0.7 percent. And the Shenzhen Composite retreated 0.4 percent.
Regional shares were mixed as the progress of a global recovery remained the focus.
In Japan, electronics makers edged higher thanks to Toshiba, which announced that it was considering a privatisation proposal by private equity firm CVC Capital Partners. The conglomerate surged more than 18 percent to its daily limit on the news. And the benchmark Nikkei eked out 0.1 percent of gains amid bargain-hunting.
Seoul's Kospi climbed 0.33 percent. Taiwan rose 0.5 percent. Australia was 0.6 percent higher. But Singapore shed 0.4 percent.