To have the upper hand
have the advantage over someone or something.
"he usually has the upper hand because he's older"
Stake a claim
1. Assert one's right to something. 2. If you stake a claim , you say that something is yours or that you have a right to it.
If you have the upper hand, you have more power than anyone else and so have control:
BalasPadam
BalasPadamcontrol or an advantage over a person or situation
have/hold the upper hand: Government troops have the upper hand in the offensive.
get/gain/take the upper hand: The last 10 minutes saw the Blues gain the upper hand.