Great Britain's Chris Adcock and Imogen Bankier lost their opening match of London 2012 to Russia's Alexandr Nikolaenko and Valeria Sorokina.
The mixed doubles pairing failed to build on a strong start as they lost 14-21 21-9 21-18.
They now face Germany's Michael Fuchs and Birgit Michels on Sunday, effectively needing a win to keep their Olympic campaign going.
beat Slovenian Maja Tvrdy 21-15 21-10.
Adcock and Bankier face Fuchs and Michels before a meeting with China's number one seeds Zhang Nan and Zhao Yunlei on Tuesday.
"We know we can play better than that, so we have got to recover, get over this one," said Bankier.
Elsewhere, China displayed their dominance as all of their doubles top seeds eased to straight-game victories.