Look to your laurels
Definition 1 of 1
Pro Tip 1/3Competition Alert
Use when someone needs to protect their position by recognizing potential challengers or threats. 
With the new intern's impressive performance, the senior employees were told to look to their laurels.
Pro Tip 2/3Awareness Call
Emphasizes the need to stay alert and not become complacent about one's achievements. 
He's been the top salesman for five years, but he should look to his laurels with the new market changes.
Pro Tip 3/3Subtle Warning
It's a gentle way to warn someone without causing alarm or offense. 
The reigning chess champion was told to look to his laurels considering the emerging young talent.