One of the two badminton pairs reinstated into the Olympic women's doubles,
after eight other players were disqualified,
is guaranteed at least a bronze medal.
Russia's Valeria Sorokina and Nina Vislova, and Canada's Alex Bruce and Michele Li won their quarter-finals, after being reprieved.
Elsewhere, in the men's singles, defending champion Lin Dan beat 2004 gold medallist Taufik Hidayat.
Badminton players disqualified
He won 21-9 21-12 in just 46 minutes.
However, the story of the day centred around the women's doubles when half of the quarter-finalists were expelled from the competition after being accused of "not using one's best efforts to win".
Two pairs from South Korea and one each from China and Indonesia made a series of basic errors in Tuesday's matches. All four pairs were accused of wanting to lose, in an attempt to manipulate the draw for the knockout stage.
Sorokina, Vislova, Bruce and Li were brought back into the competition - and duly won their quarter-finals.
Sorokina and Vislova will play Chinese second seeds Tian Qing and Zhao Yunlei in the semi-final, with Bruce and Li up against Japan's Mizuki Fujii and Reika Kakiiwa.
In the women's singles, Sayaka Sato of Japan left the Wembley Arena courts in tears after pulling out of her last-16 tie with Denmark's Tine Baun through injury.