Upper critical field of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>RuO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math> under in-plane uniaxial pressure

In-plane uniaxial pressure has been shown to strongly tune the superconducting state of Sr2RuO4 by approaching a Lifshitz transition and associated Van Hove singularity (VHS) in density states. At VHS, $T_c$ in- out-of-plane upper critical fields are all enhanced, latter changed its curvature as function temperature from convex concave. However, due strain inhomogeneity it not possible so far determine how change with strain. Here, we show dependence both fields, which was achieved an improved sample preparation. We find that in-plane field is mostly linear $T_c$. On other hand, varies higher power $T_c$, peaks at VHS. The strong increase magnitude form $H_\mathrm{c2||c}$ occur very close strain, points enhancement states gap transition.