We elucidate the relation between Painlev\&#039;e equations and four-dimensional<br />
rank one ${\cal N= 2}$ theories by identifying the connection associated to<br />
Painlev\&#039;e isomonodromic problems with the oper limit of the flat connection of<br />
the Hitchin system associated to gauge theories and by studying the<br />
corresponding renormalisation group flow. Based on this correspondence we<br />
provide long-distance expansions at various canonical rays for all Painlev\&#039;e<br />
functions in terms of magnetic and dyonic Nekrasov partition functions for<br />
${\cal N= 2}$ SQCD and Argyres-Douglas theories at self-dual Omega background<br />
$\epsilon_1+\epsilon_2= 0$, or equivalently in terms of $c= 1$ irregular<br />
conformal blocks.