As Fabio mentioned, there are two meanings of 大败.

1) to defeat; to inflict a defeat on somebody

2) to suffer a defeat; to be defeated

Simply speaking, when we say someone 大败, which means to suffer a defeat; to be defeated. eg. 敌军大败   The enemy was defeated. While when we say A大败B , which means A defeated B.

This is a trick question

Both sentences say 北京队 won but says it in a different way.

http://www.italki.com/question/203171

Thanks May, now it is clearer also for me.

是篮球吗?那一定是北京金隅