  We establish a good lambda inequality relating to the distribution function
of Riesz potential and fractional maximal function on $\left(\mathbb{R}^n,
d\mu\right)$ where $\mu$ is a positive Radon measure which doesn't necessarily
satisfy a doubling condition. This is extended to weights $w$ in
$A_{\infty}(\mu)$ associated to the measure $\mu$. We also derive potential
inequalities as an application.
