Liberal Dictionary English Dictionary
Surpass someone in his or her own specialty or undertaking. For example, Jean knew that if she matched the new store’s discount she would keep all her customers and beat the new competitors at their own game. The use of game for any kind of undertaking or scheme dates from the mid-1200s.
Don’t try to beat Them at Their Own Game. Love Yourself – SelfLove
Beat the Government at their own GAME – YouTube
THAT FEELING WHEN YOU BEAT SOMEONE WITH THEIR OWN ABILITY ABILITY