GB men's basketball team lost their opening match of the London Games to Russia 95-75.
It was GB's first Olympics basketball appearance since 1948.
Things started really well for the home side and they led 18-17 following a three-pointer from star player Luol Deng.
But Russia began to gain control and after opening up a 49-34 lead at the half-time, they never looked in danger.
GB forward Pops Mensah-Bonsu said his team must get over the defeat quickly.
"We'll look at the tape and bounce back. We felt our half-court defence was good and they struggled against it," he said.
Elsewhere reigning champions the USA , powered to a 97-71 victory over France.
Meanwhile, GB's next opponents Brazil earned a hard-fought 75-71 win over Australia, while Spain defeated China 97-81.