Badminton mixed doubles pair Tang Chun-man and Tse Ying-suet revived their medal chances with a second victory in the group stage.
Tang and Tse put up an exceptional performance to fend off German pair Mark Lamsfuss and Isabel Herttrich to claim the last ticket in the quarter-finals from their group.
The Hong Kong pair, ranked 13th in the world, beat Lamsfuss and Herttrich 22-20, 20-22, 21-16.
The quarter-finals will be played tomorrow.
On a day when Hong Kong won its first gold medal of the Games courtesy of fencer Edgar Cheung Ka-long in individual foil and swimmer Siobhan Haughey qualified for the semi-finals the 200-meter freestyle, Tang and Tse provided the other highlight of the day.
In other fronts, Hong Kong's Oscar Coggins finished 33rd in triathlon yesterday, as Norwegian Kristian Blummenfelt won gold in a race disrupted by a bizarre false start.
Coggins showed promise in his debut in the Olympic Games, as the 21-year-old finished nearly four minutes behind the winner, after a 1.5-kilometer swim, 40km bike ride and a 10km run under temperatures of 33 degrees Celsius.
Blummenfelt, 27, crossed the line in one hour, 45 minutes and four seconds.
Jack Yee of Britain took silver, 11 seconds behind the winner, while Hayden Wilde of New Zealand took bronze.
But the main talking point after the race was the chaotic start to the event, which saw about half of the 56 competitors forced to return to the starting pontoon after swimming for about 40 seconds with a boat obstructing the rest of the field.
Meanwhile, both Hong Kong players in the men's singles of table tennis were unable to reach the round of 16.
Lam Siu-hang, ranking 95th in the world, was eliminated by Japan's Harimoto Tomokazu, currently ranked fourth in the world.
The 24-year-old Lam battled it out with Harimoto before losing 4-1.
Earlier, Hong Kong No 1 Wong Chun-ting, currently ranked 20th in the world, bowed out to Chinese Taipei's Chuang Chih-yuan 4-2.
He was eliminated a day earlier from the mixed doubles events with partner Doo Hoi-kem.
Tse Ying-suet hits a shot next to Tang Chun-man. AFP
